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On January 21st, 2024, a meter-sized asteroid (2024 BX1) entered Earth’s atmosphere and exploded over Berlin at 12:33 am UTC (07:45 pm EST; 04:33 pm PST). Before it reached Earth, 2024 BX1 was a Near-Earth Asteroid (NEA) with an orbit that suggests it was part of the Apollo group. The fragments have since been located by a team of scientists from the Freie Universität Berlin, the Museum für Naturkunde (MfN), the German Aerospace Center (DLR), the Technische Universität Berlin, and the SETI Institute and identified as a rare type of asteroid known as “aubrites.”

The name aubrites comes from the village of Aubrés in France, where a similar meteorite fell on September 14th, 1836. The team responsible for recovering samples of this latest meteorite was led by SETI Institute meteor astronomer Dr. Peter Jenniskens and MfN researcher Dr. Lutz Hecht. They were joined by a team of staff and students from the MfN, the Freie Universität Berlin, the DLR, and the Technische Universität Berlin days after the meteor exploded in the sky. Together, they found the meteor fragments in the fields just south of the village of Ribbeck, about 50 km (31 mi) west of Berlin.

Aubrite meteorite from asteroid 2024 BX1, photographed at the Museum für Naturkunde Berlin by Laura Kranich, a Freie Universität MSc student and member of the Arbeitskreis Meteore, who participated in the search and found this meteorite near the village of Ribbeck, Germany. Credit: SETI Institute

Finding the fragments was a major challenge because of the peculiar appearance of aubrites, which resemble rocks like any other from a distance but are quite different to look at up close. Whereas other types of meteors have a thin crust of black glass caused by the extreme heat generated by passing through the atmosphere, aubrites have a mostly translucent glass crust. Christopher Hamann, a researcher from the Museum für Naturkunde, was involved in the initial classification and participated in the search. As he related in a SETI Institute press release:

“Aubrites do not look like what people generally imagine meteorites to look like. Aubrites look more like a gray granite and consist mainly of the magnesium silicates enstatite and forsterite. It contains hardly any iron and the glassy crust, which is usually a good way to recognize meteorites, looks completely different than that of most other meteorites. Aubrites are therefore difficult to detect in the field.”

The asteroid (2024 BX1) was first spotted by Hungarian astronomer Dr. Krisztián Sárneczky using one of the telescopes at the Konkoly Observatory in Budapest. The task of tracking it and predicting where it would impact Earth’s atmosphere was performed by NASA’s Scout mission and the ESA’s Meerkat Asteroid Guard impact hazard assessment systems, with Davide Farnocchia of JPL/Caltech providing frequent trajectory updates. Like the Chelyabinsk meteorite that exploded over southern Russia in 2013, the explosion was witnessed by many and filmed (though the explosion caused no damage).

This was Jenniskens’ fourth guided recovery of a small asteroid that fell to Earth, the previous events being a 2023 impact in France, a 2018 impact in Botswana, and a 2008 impact in Sudan. As he explained, this latest asteroid was particularly challenging to track down:

“Even with superb directions by meteor astronomers Drs. Pavel Spurný, Jirí Borovicka, and Lukáš Shrbený of the Astronomical Institute of the Czech Academy of Sciences, who calculated how the strong winds blew the meteorites and predicted that these could be rare enstatite-rich meteorites based on the light emitted by the fireball, our search team initially could not easily spot them on the ground. We only spotted the meteorites after a Polish team of meteorite hunters had identified the first find and could show us what to look for. After that, our first finds were made quickly by Freie Universität students Dominik Dieter and Cara Weihe.”

Chelyabinsk fireball recorded by a dashcam from Kamensk-Uralsky north of Chelyabinsk where it was still dawn. A study of the area near this meteor air burst revealed similar signatures to the Tall el_Hammam site.

This past week, Jenniskens’ colleagues at the MfN officially announced that they had conducted their first analyses of one of the meteor fragments. The process was led by Dr. Ansgar Greshake, the scientific head of the MfN’s meteorite collection, which consisted of an electron beam microprobe studying the mineralogy and chemical composition of the fragments. Their results revealed they the fragments are consistent with an achondrite meteor of the aubrite type, which were submitted to the International Nomenclature Commission of the Meteoritical Society on February 2nd, 2024, for verification.

“Based on this evidence, we were able to make a rough classification relatively quickly,” said Greshake. “This underlines the immense importance of collections for research. So far, there is only material from eleven other observed falls of this type in meteorite collections worldwide.”

Further Reading: SETI

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When doing the marketing for the James Webb Space Telescope (JWST), NASA and the other telescope contributors liked to point out how it would open up the early universe to scrutiny. They weren’t exaggerating, and now scientific studies are starting to proliferate that show why. A new study published by authors from Harvard, the University of Arizona, and the University of Cambridge used three surveys produced by the JWST to analyze the supermassive black holes at the center of early galaxies. And they found they were much different than the one at the center of our own, at least in terms of relative size.

Fabio Pacuci and his coauthors were looking at galaxies located 12-13 billion light years away – some of the earliest formed ones in the universe. In particular, they were looking at the size of the black holes in the center of those galaxies compared to the size of the stars the galaxies are composed of. 

For example, the ratio of the weight of stars to the weight of the supermassive black hole in the center of our home Milky Way Galaxy is about 1000 to 1 – meaning the total mass of the stars outweighs the black hole by a factor of 1000. Similar ratios have been found for other galaxies with similar ages, such as Andromeda.

Fraser describes some of what we know about black holes’ place in the universe.

However, the study found something quite different in older galaxies. Their ratios were more like 100 to 1 or even as low as 1 to 1, where the supermassive black hole weighed as much as all of the stars orbiting it. This difference has “important implications for the study of the first population of black holes,” according to Xiaofui Fan, one of the study’s coauthors, as mentioned in a recent press release. 

There has been an ongoing discussion about those early black holes, focused primarily on what the precursors of the supermassive black holes we know today looked like. Two competing theories have taken root for those precursors – “heavy” seeds and “light” seeds. In the “heavy” seed scenario, the seed materials for the supermassive black hole would mass around 10,000 to 100,000 times the mass of our Sun, while “light” seeds would weigh in at about 100 to 1,000 times.

According to the new paper, the “heavy” seed model is more likely. It would be more likely to create large supermassive black holes, such as those seen in the JWST data, by allowing the accumulation of material from giant gas clouds to coalesce around a much larger starting mass. Simulations of this seed theory also predicted that the black holes in early galaxies would roughly mass the same as the galaxies they were surrounded by.

Primordial black holes, while still theoretical, could help shed some light on the questions the paper tries to address, as Fraser explains.

As any good scientist will tell you, if a theory or a model makes a stunning different prediction, and further data collection aligns with that prediction, then it’s a very good sign for the theory. That is precisely what happened in the case of the heavy seed theory and the JWST data. As described in the paper, the data closely fits the prediction made by heavy-seed modelers.

But it’s not quite an open-and-shut case yet. Many astronomers still don’t know about the early black hole formation process. But JWST isn’t done yet, and the paper’s authors are hopeful that further data releases will help shed light on how those seeds grow into fully-fledged black holes and what that means for how the universe was more generally formed.

For now, they’ll have to wait for some more data. But with JWST still going strong, it seems there will be plenty more papers peering into the early universe enabled by humanity’s most impressive space telescope.

Learn More:
Harvard CfA – Unexpectedly Massive Black Holes Dominate Small Galaxies in the Distant Universe
Pacucci et al. – JWST CEERS and JADES Active Galaxies at z = 4–7 Violate the Local M•–M? Relation at >3?: Implications for Low-mass Black Holes and Seeding Models
UT – Growing Black Hole Seen Only 470 Million Years After the Big Bang
UT – Early Black Holes Were Bigger Than We Thought

Lead Image:
Distant Universe versus Nearby Universe.
Credit: CfA/Melissa Weiss

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The poetic-minded among us like to point out how Nature is a dance. If they’re right, then galaxies sometimes form unwieldy pairs. With the Hubble Space Telescope, we can spot some of these galactic pairs as they approach one another.

Part of galactic evolution involves galactic interactions and mergers. When galaxies interact gravitationally, it can create streams of gas and dust that stretch for light-years.

ARP 271 is one of the interacting pairs of galaxies imaged by Hubble. ARP 271 contains NGC 5427 and NGC 5426. The pair is about 130 million light-years distant and about 130 million light-years across.

The pair have been interacting since long before humanity ever appeared and will continue to interact for tens of millions of years. It’s not clear if the pair will eventually merge.

Powerful interactions between massive galaxies like these can trigger star birth in the streams of gas and stars that bridge the galaxies. The bridge between the pair is faint in these images, but it’s there in the lower right corner of the Hubble image, and young bright blue stars highlight it. The bridge feeds gas back and forth between the galaxies, fuelling star formation.

Hubble provided the image of NGC 5427, while a ground-based observatory provided the image of the ARP 271 pair. Image Credits: Ground-based image: DECam Victor M. Blanco/CTIO; Hubble image: NASA, ESA, and R. Foley (University of California – Santa Cruz); Processing: Gladys Kober (NASA/Catholic University of America)

However, the same interactions can sometimes quench star birth. High-velocity interactions can heat gas so much that it weakens star formation.

Most galaxies have interacted with others, even if they haven’t merged. There are likely few galaxies that have interacted with a neighbouring galaxy at one time or another. There may be no pristine galaxies. Our own Milky Way galaxy is on course to interact with the neighbouring Andromeda galaxy in about 4.5 billion years.

Interacting galaxies are found throughout the Universe, sometimes as dramatic collisions that trigger bursts of star formation, on other occasions as stealthy mergers that result in new galaxies. These new images of colliding galaxies were released from the several terabytes of archived raw images from the NASA/ESA Hubble Space Telescope to mark the 18th anniversary of the telescope’s launch. Image Credit: NASA/ESA

Astronomers think that ARP 271 could serve as a blueprint for the eventual Milky Way/Andromeda interaction.

About 25% of galaxies are currently merging with others, according to the Harvard and Smithsonian Center for Astrophysics. Even more of them are interacting gravitationally, if not merging. The Milky Way is interacting with the Large and Small Magellanic Clouds, two irregular dwarf galaxies orbiting the Milky Way. That interaction is also creating a stream of gas called the Magellanic Stream.

The Magellanic Stream trails behind the Small and Large Magellanic Clouds – visible below the Milky Way’s galactic disk to the right. Ahead of the Clouds is another structure called the Leading Arm. This is a false colour image – the Stream, Arm and Magellanic Bridge between the two Clouds are only visible in radio light. Image Credit: NRAO

It took billions of years of mergers for small galaxies to combine and become the massive galaxies we see today. Giant ellipticals are the largest galaxies in the Universe, and some are 700,000 light-years across. Astronomers are almost certain they only grew so massive through mergers.

Human lifetimes are inconsequentially short compared to the lives and affairs of galaxies. So is human civilization. We can catch glimpses of galaxies interacting, and we can catch these interactions in different stages. But we’ll never see the final results.

The dance of galaxies started long before we were here and will continue long after we’re gone.

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In a disheartening turn of events, NASA’s Jet Propulsion Laboratory has announced that it’s laying off about 8% of its workforce. That means that about 530 JPL employees will be let go, along with about 40 employees of the Lab’s contractors. That sucks for the people being let go, but the bigger concern for the rest of us is what will happen to upcoming missions like Mars Sample Return (MSR)?

These layoffs have nothing to do with the individuals affected or with JPL’s activities. It’s all budget wrangling, something that is a near-constant in a democracy. There’s only so much money, and there’s always an excess of things to spend it on.

In this case, NASA has passed on funding constraints to JPL, and while JPL has tried to manage them, the result is this announcement.

“After exhausting all other measures to adjust to a lower budget from NASA, and in the absence of an FY24 appropriation from Congress, we have had to make the difficult decision to reduce the JPL workforce through layoffs,” a statement from JPL explained.

Without a Fiscal Year 2024 appropriation, there isn’t enough money in NASA’s budget to keep everything going. In fact, NASA and JPL have been waiting for an appropriation of some kind of final word on 2024 funding for the MSR mission but haven’t received any clear indication. JPL has been dealing with the uncertainty by streamlining operations and making changes in the last several months, but now they say their hand is forced.

“While we still do not have an FY24 appropriation or the final word from Congress on our Mars Sample Return (MSR) budget allocation, we are now in a position where we must take further significant action to reduce our spending, which will result in layoffs of JPL employees and an additional release of contractors,” said JPL’s statement.

“These cuts are among the most challenging that we have had to make, even as we have sought to reduce our spending in recent months.”

What will this mean for the Mars Sample Return joint mission with the ESA? What will it mean for the Perseverance Rover, as it actively collects and caches samples on the Martian surface?

The Perseverance Mars rover took this selfie with several of the 10 sample tubes it deposited on the Image Credit: NASA/JPL-Caltech/MSSS.

It’s nothing new for organizations to face budget constraints and layoffs. But there’s a sense of immediacy with these layoffs. It’s all happening very quickly, and that can be especially concerning in an organization whose activities rely on meticulous and advanced planning involving highly complex systems. It takes years, even decades, to pull a mission like MSR together, and lack of funding consistency makes it all the more difficult.

Universe Today publisher Fraser Cain interviewed Casey Dreier about this issue. Dreier is Chief of Space Policy at The Planetary Society, and their discussion is on YouTube.

“How do you clean out 8% of your workforce overnight?”

Casey Dreier, The Planetary Society

“A good number of people very rapidly; this is all happening in a single day,” said Dreier.

The layoffs aren’t exactly surprising. There’ve been indications that it may come to this, but the actuality of it is still sinking in. “This has been stirring for a while. JPL started laying off contractors last month,” Dreier said. JPL has also had a hiring freeze in place since September.

“How do you clean out 8% of your workforce overnight?” Dreier asked.

With great sensitivity, according to JPL Director Laurie Leshin. “Our desire in this process is that impacted employees quickly get to the point where they will receive personalized attention during this transition,” Leshing wrote in a memo to JPL employees.

“Without an approved federal budget including final allocation for MSR FY24 funding levels, NASA previously directed JPL to plan for an MSR budget of $300M,” Leshin wrote in a memo. The $300 million number is at the low end of historical congressional markups to NASA’s budget. It’s also a 63% decrease from FY 23. Nobody can say that NASA and JPL have been wreckless in their assumptions about funding.

These layoffs may not be entirely due to a lack of money. They could be a symptom and a result of the dysfunctional political situation playing out in the US Congress. The political class is mired in ongoing disputes, and it’s preventing some important work from being done in a timely fashion.

“Really though, at the end of the day, a stalemate between two chambers of Congress is driving the sudden layoffs rather than a more orderly wind-down,” Dreier said.

The upcoming Artemis missions attract a lot of attention for sending astronauts to the lunar surface for the first time in more than 50 years. But in purely scientific terms, many of us are excitedly awaiting the Mars Sample Return. Artemis is Human Spaceflight, and MSR is Science. By bringing samples home from Mars, we’ll be poised to uncover important answers to questions about Mars’ ancient past and whether life ever existed there.

An independent review of the MSR uncovered some serious problems. According to Dreier, that report stated that the mission cannot be completed with any budget. “MSR is a deep-space exploration priority for NASA,” the report states. “However, MSR was established with unrealistic budget and schedule expectations from the beginning. MSR was also organized under an unwieldy structure. As a result, there is currently no credible, congruent technical, nor properly margined schedule, cost, and technical baseline that can be accomplished with the likely available funding.”

How do these new cutbacks play into this?

“At the stage MSR was in, there had been no formal cost projections,” Dreier said. That’s typical of complex space missions like MSR because there’s nothing to compare it to and gauge it by. As Dreier points out, NASA likely spent tens or hundreds of millions of dollars before they even knew what the final cost would be. That money is spent determining if the mission can even be built at all and in what timeline. That’s the mission formulation stage.

The ESA/NASA Mars Sample Return will be one of the most complex missions ever devised. It’s impossible to know exactly how much it will cost. Image Credit: ESA

However, Dreier explained, the Decadal Survey prioritized the MSR mission and plugged in a cost of about $5.3 billion US. “The independent review, however, said this project is likely to cost between 9 to 11 billion dollars,” said Dreier. (Watch the video to see Fraser wince at that.) That number could easily go higher if missions like the JWST tell us anything. And the MSR mission is extremely complex, involving different vehicles, companies, and agencies all working together.

So, where does this leave the MSR? Only time will tell.

MSR is an extraordinarily complex undertaking. There are so many parts and pieces to it that if one thing goes wrong, we get nothing from it. We either get samples, or we don’t, and if we don’t, the mission provides nothing, and all that money is gone.

These staffing and budget cutbacks aren’t MSR’s first headwinds. After the Independent Review Board’s report, NASA formed a committee to examine MSR and come up with a response. This has taken months and has been taking place behind closed doors. “All that we know is that MSR is in major trouble, and NASA has been thinking about what to do but has not said what it’s going to do,” Dreier said. “That lack of path forward from NASA has made the project appear vulnerable politically.”

“Blood’s in the water,” Dreier said. It may be that the experience with the JWST and its ballooning cost overruns are contributing to the reluctance to fund MSR.

An artist’s illustration of the James Webb Space Telescope. With the JWST’s steady stream of stunning results, it’s easy to forget that the space telescope ran the gauntlet of cost overruns, ballooning budgets, and wary budget-minded politicians. That experience is hanging over the head of the MSR mission. Image Credit: NASA/JPL/Caltech

Dreier is a spokesperson for the Planetary Society, and he says quite clearly that while the Society is in favour of a Mars sample mission, they’re not wedded to this version of it.

Who knows what will happen? There’s a certain ‘fog of war’ element to all of this.

There’s no question that getting samples from Mars to labs here on Earth is the next step in understanding the planet. The Decadal Survey doesn’t take ill-considered positions, and neither does the Planetary Society.

NASA and JPL will survive this lack of funding. But will the MSR in its current state survive it?

That seems to be anybody’s guess right now. But as Dreier says, “The politics around this are becoming sharp-elbowed.”

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In the Fall of 1989, the Galileo spacecraft was launched into space, bound for Jupiter and its family of moons. Given the great distance to the king of planets, Galileo had to take a roundabout tour through the inner solar system, making a flyby of Venus in 1990 and Earth in 1990 and 1992 just to gain enough speed to reach Jupiter. During the flybys of Earth Galileo took several images of our planet, which astronomers have used to discover life on Earth.

The idea of “discovering” life on Earth in the 21st century might seem a bit ridiculous, but the study is quite useful to astronomers seeking life on other worlds. Since we know there is life on Earth as well as the geography and diversity of our world, images from Galileo can be used as a test bed to compare with images of exoplanets. We are still in the early stages of making direct images of some exoplanets, and astronomers are still learning what those images might tell us.

A detailed image of Earth vs how it would appear as a distant exoplanet. Credit: NOAA/NASA/Stephen Kane

So in this work, the team focused on what are known as disk-integrated images. This is where light from a planet is taken as a whole. Instead of a detailed image of Earth such as the one above, the team looked at integrated images from the Limited Solid State Imager (SSI). The disk-integrated images it gathers are similar to the images we can capture of exoplanets. They then looked at the overall brightness and spectra of these images to see what they could tell us about Earth.

One of the things the authors found is that much of the spectral data in the integrated images is washed out, making it difficult to identify particular biosignatures. That was somewhat expected since the Galileo cameras were optimized for Jupiter, which is much more distant from the Sun and therefore much dimmer. However, the team was able to detect an oxygen absorption line, verifying that our planet has an oxygen-rich atmosphere. By itself the presence of oxygen wouldn’t conclusively prove that life exists on Earth, but it is a good start.

How brightness ratios of red/violet and UV/violet show evidence of Earth’s terrain. Credit: Strauss, et al

More interestingly, the team was able to look at the changes in albedo, or reflective brightness as Earth rotates. From this, they could get a very rough idea of continents and oceans on Earth. From this they could prove that Earth has a mixture of both lands and oceans, making it well-suited for habitability.

The biggest benefit of this study and others like it is that it provides a baseline for potentially habitable exoplanets. Seen from a distance and with limited resolution, this is how a life-bearing planet appears. As astronomers find exoplanets that appear similar, they will know they are on the right track to discovering life on other worlds.

Reference: Strauss, Ryder H., et al. “Exoplanet Analog Observations of Earth from Galileo Disk-integrated Photometry.” The Astronomical Journal 167.3 (2024): 87.

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It’s been a while since NASA has had a spaceplane on the launchpad but this now feels closer than ever again. Their new prototype cargo spaceplane known as Dream Chaser is now undergoing vibration and vacuum testing at the Neil Armstrong test facility. The tests sound a little strange perhaps but on launch and during re-entry it will most definitely experience shaking during these phases of the flights. 

The Dream Chaser spaceplane has been designed to attach to the top of a conventional Vulcan Centaur rocket and land like a plane. Its propulsion is to be a cluster of propane and nitrous oxide Vortex engines which differs from the originally planned hybrid rocket engines. The plane has an expendable cargo module called Shooting Star which can carry an additional 4,500 kg of cargo. It’s been designed so that it can dispose of unwanted cargo by burning up on re-entry. 

The spaceplane and its new cargo unit have been going through rigorous testing at the NASA facility since the 1st February. It’s without doubt one of the worlds largest and best equipped test facilities that can simulate the harsh conditions experienced during space flight. 

First up for Dream Chaser is the shock test which is the jolt experienced when the plane is separated from the cargo module. It stays on the spacecraft shaker system (a giant table supported on pneumatics and springs that can shake a payload/spacecraft at up to 100 vibrations per second to simulate the violent shaking experienced during launch) to undergo vibration tests before another shock test is completed. On completion of the tests, the spacecraft will undergo a rigorous examination to identify any issues that may have surfaced. 

Once Dream Chaser has completed this first suite of tests, it will move into the huge vacuum chamber to experience the lower ambient pressures experienced in space. Low temperatures and simulated dynamic solar heating will all go further to test the space planes readiness for space. 

The Dream Chaser space plane atop a United Launch Alliance Atlas V rocket. Image Credit: SNC

If the tests are successful then Dream Chaser is well on its way to its first uncrewed test flight to the International Space Station later in 2024 as part of NASAs Commercial Resupply program. It won’t be completely empty though, it will deliver just over 3,500kg of cargo to the ISS. 

If the first flight is successful then there are variants of the plane under development including an additional crewed variant that can carry up to seven passengers to low Earth orbit and a National Security Variant, the details of which are being kept under strict security protocols.

Source : NASA Spaceplane Shaken at NASA Test Facility

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Comet 12P Pons-Brooks takes center stage this Spring.

Something is definitely up with the 12th periodic comet in the catalog. We’re talking about Comet 12P Pons-Brooks, set to reach the first of two perihelia for the 21st century this Spring. And the timing couldn’t be better, as the comet will also sit near the Sun just two weeks prior during the total solar eclipse of April 8th 2024, spanning the North American continent from the southwest to the northeast. If the comet over-performs—a long shot, but multiple outbursts in 2023 suggest it just might—we could be in for the added treat of a naked eye comet near the Sun during totality.

The planets, Comet 12P, and the eclipsed Sun on April 8th, 2024 as seen from Mapleton, Maine. Credit: Starry Night. The Intriguing Tale of Comet 12P

As of writing this, the comet is at magnitude +7.5 ‘with a bullet,’ well within range of binoculars. The comet will reach perihelion on April 21st, 2024, at 0.78 Astronomical Units (AU) from the Sun.

The orbit of Comet 12P. NASA/JPL-Horizons

On a 71 year orbit (just a tad shorter than Halley’s Comet) Comet 12P can reach +5th magnitude on a favorable apparition. The name for the comet comes from the original discoverer astronomer Jean-Louis Pons, who first spotted the comet from the Marseilles Observatory in July 1812, and William Robert Brooks, who recovered the comet on the next apparition and cliched its periodic nature in 1883.

Comet 12P Pons-Brooks, sketched by astronomer E.E. Barnard in 1884. Public Domain image. What 2023 Outbursts Mean for 2024

Keep in mind, an outburst near perihelion could vault Comet 12P up into naked eye brightness. Clearly, 12P Pons-Brooks has an active nucleus, estimated to be about 30 kilometers across. For context, Hale-Bopp had a nucleus estimated at 40-80 kilometers across. Comet 12P reached magnitude +4.5 during the last pass in 1954.

Comet 12P Pons-Brooks in December 2023. Image credit: Dan Bartlett.

“My own thoughts on 12P is that it has been a wonderful surprise because it has been so active and with such unusual features,” astrophotographer Eliot Herman tells Universe Today. “There were predictions that 12P could be interesting from its past observations as an active comet, but I read the papers from prior passes and there are not that many images or drawings, and it appears that the observers of the era did not engage in constant monitoring.”

Herman is also collaborating with the British Astronomy Association’s campaign to observe the comet.

Tales of Two Comets

“You can compare 12P with 1P (Halley),” says astrophotographer Michael Jaeger. “Both are long-known periodic comets with a similar orbital period. Both are absolutely similarly bright. While 1P has its perihelion between Venus and Mercury, 12P only makes it slightly above the orbital plane of Venus.” This means that Pons-Brooks is generally not as spectacular as Halley’s Comet near perihelion. “Photographically, 12P already presents itself beyond the orbital plane of Mars with a faint ion tail that is more than 2 degrees long,” says Jaeger. “This will become significantly brighter over the next two months. this will give photographers the chance to take some spectacular images.”

Outbursts in 2023 shot the comet up a full 100-fold in brightness or five full magnitudes, reminiscent of the 2007 outburst from Comet 17P/Holmes which shot it up an amazing 15 magnitudes (one million times!) into naked eye brightness overnight. The 2023 outbursts gave Comet 12P/Pons-Brooks a ‘devil’s horns‘ look, reminiscent of Star Wars’ Millennium Falcon.

The ‘horned comet’ in 2023. Image credit: Eliot Herman

The 2024 apparition sees the comet well-placed for northern hemisphere observers at dusk, low to the northwest. The comet is approaching us along our line of sight and loiters across the constellations Lacerta into Andromeda and Pisces from February through April before taking the plunge southward across the ecliptic. After 2024, we won’t see Comet 12P Pons-Brooks again until 2095.

The dusk path of the comet, looking to the northwest 30 minutes after sunset. Credit: Starry Night.

Here’s a look at comet 12P month-by-month in early 2024. As always, ‘passes near’ means less than one degree apart, unless otherwise noted:

February

9-Passes into the constellation Lacerta the Lizard

12-Passes near the +4th magnitude star 1 Lacertae

22-Passes into Andromeda the Princess

25-Passes 6 degrees from the Blue Snowball Nebula NGC 7662

The celestial path of comet 12P, from February through April. Credit: Starry Night March

9-Passes 8 degrees from the Andromeda Galaxy Messier 31

12-Passes between the stars Delta and Pi Andromedae

15-Passes into the constellation of Pisces the Fishes

19-Passes near the +4.5 magnitude star Tau Piscium

22-Photo op: passes just 3 degrees from the Pinwheel Galaxy Messier 33

27-Nicks the corner of the constellation Triangulum, then heads into the constellation of Aries the Ram

29-Passes near +4th magnitude star Lambda Arietis

31-Passes very near (less than 6’) from the +2nd magnitude star Hamal (Alpha Arietis)

The light curve for comet 12P. Adapted from Seiichi Yoshida’s Weekly Information About Bright Comets. April

8-Sits 24 degrees east of the Sun, during the total solar eclipse

11-Passes the ecliptic southward

14-Passes 3 degrees from Jupiter

20-Passes into the constellation of Taurus the Bull

21-Passes near 3.7 mag Xi Tauri, at perihelion

A recent animation of Comet 12P. Image credit: Michael Jaeger.

From there, the comet makes its closest Earth approach on June 2nd at 1.55 AU distant… but is much less favorably placed for observation in the southern constellation Lepus the Hare.

Don’t miss a chance to catch comet 12P/Pons-Brooks, coming to a sky near (or above) you.

The post The Comet vs. the Eclipse: 12P/Pons-Brooks Heads Towards Perihelion in April appeared first on Universe Today.

Supernova are a fascinating phenomenon and have taught us much about the evolution of stars. The upcoming Nancy Grace Roman telescope will be hunting the elusive combination of supernovae in a gravitational lens system. With its observing field 200 times that of Hubble it stands a much greater chance of success. If sufficient lensed supernovae are found then they could be used to determine the expansion rate of the Universe. 

Supernova are stellar corpses, the remains of supermassive stars that have reached the end of their lives. The events mark one of the most energetic processes whose light can be seen across the cosmos.  Astronomers have studied their light output for decades to identify which type of supernova they are so that they can calculate the distance to their host galaxy and even the expansion rate of the Universe. This approach however, relies upon measuring brightness.

Another equally fascinating phenomenon are gravitational lenses. In these chance alignments of galaxies, the gravitational force of the intervening objects bends the light from the more distant, magnifying it and providing a new window on more distant regions of space. 

Gravitational lenses are chance alignments and reasonably rare but the liklihood of a supernova occurring in a gravitational lensed galaxy is even rarer. Enter NASA’s Nancy Grace Roman Space Telescope due for launch in 2027. Its impressive wide field will allow astronomers to explore great swathes of sky at once, souring the Universe for gravitationally lensed supernovae. Not only will it be able to capture a greater region of the sky but using the High Latitude Time Domain Survey will observe the same region of sky over and over again over a period of two years to identify any changes over time. 

Artist’s impression of the Nancy Grace Roman Space Telescope, named after NASA’s first Chief of Astronomy. When launched later this decade, the telescope should make a significant contribution to the study of FFPs. Credits: NASA

The team is led by Lou Strolger from the Space Telescope Science Institute is already working on techniques to find the rare events through a project funded by NASA’s Research Opportunities in Space and Earth Sciences. They will use simulated images of gravitational lenses to help them prepare. Given the launch of the 2.4m wide field telescope is still three years away the team has time to develop the techniques and processes so they can hit the ground running once the telescope is available. 

Already there have been eight likely gravitationally lensed supernovae discoveries that are being analysed and that’s using the Hubble Space Telescope and the James Webb Space Telescope. The Nancy Grace telescope is a game changer and, given enough time can take us a step closer to understanding the expansion rate of the Universe and give us more of an insight into the nature of dark matter and dark energy too. Exciting times.

Source : NASA’s Roman to Use Rare Events to Calculate Expansion Rate of Universe

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A recent preprint investigates how chickpeas have been successfully grown in lunar regolith simulants (LRS), marking the first time such a guideline has been established not only for chickpeas, but also for growing food for long-term human space missions. This study was conducted by researchers from Texas A&M University and Brown University and holds the potential to develop more efficient methods in growing foods using extraterrestrial resources, specifically with NASA’s Artemis program slated to return humans to the lunar surface in the next few years.

From Dust To Seed: A Lunar Chickpea Story https://t.co/qhCSMxheTe #astrobiology #spaceag #spacebiology #agriculture #Artemis pic.twitter.com/q7oR9hfDx6

— Astrobiology (@astrobiology) January 24, 2024

“The Moon doesn’t have soil like Earth does,” said Jessica Atkin, who is a M.S. student in Soil Science at Texas A&M University and lead author of the study. “On Earth, the soil has organic material filled with nutrients and microorganisms, which support plant growth. Those are missing on the moon. This adds to other challenges, such as reduced gravity, radiation, and toxic elements.”

For the study, the researchers compared the relationship between Vermicompost (VC) and Arbuscular Mycorrhizal Fungi (AMF) with the goal of creating a productive LRS structure for successfully growing chickpeas (Cicer arietinum). AMF is often used to aid in plant growth hormone production while VC contains worm manure that is used to enhance seed growth. The team analyzed various combinations of 25%, 50%, 75%, and 100% LRS, with each being mixed with corresponding measurements of VC and AMF. While the experiments were scheduled to run for 120 days, the researchers discovered 100% seed growth by day 16, and continued to grow throughout week 6, 9, and 11, as well.

Image of chickpea plants while growing in a 75% mixture of lunar regolith simulant. (Texas A&M AgriLife photo by Jessica Atkin)

The study notes, “We report the first instance of growing chickpea (Cicer arietinum) in lunar regolith simulants. We used soil regeneration techniques common on Earth with LRS for the first time, using both AMF and VC. We also achieved the first documented chickpea yield in an LRS mixture. Our results show that regeneration methods used on Earth soils can help condition lunar regoliths. Despite promising results, all plants in LRS showed signs of chlorophyll deficiency.”

Chlorophyll has the vital responsibility for absorbing light, most often sunlight, for the plant to use for photosynthesis. While the team did note chlorophyll deficiencies, they also noted, “By week seven, a visible improvement in chlorophyll levels suggests successful AMF colonization in the inoculated group” with the inoculation occurring due to the incorporated AMF.

Image of the chickpea plants after five weeks displaying a diversity of chlorophyll. (Texas A&M AgriLife photo by Jessica Atkins)

As noted, this study comes as NASA is planning on sending humans back to the Moon with its Artemis program in the next few years. Successfully growing plants using lunar regolith is also known as in situ resource utilization (ISRU), which could significantly reduce the need for constant resupply of food or soil from Earth. While not directly mentioned in the study or by the researchers, this study mirrors NASA’s Lunar Surface Innovative Initiative whose goal is to develop technologies on the Moon that could be used for future crewed missions to Mars.

“The novelty about using vermiculture is that it can all be done in space, whether in a space station or on the moon, reducing the need for resupply missions,” said Atkin.

This novelty not only includes the International Space Station (ISS) and upcoming Artemis missions but could also include commercial space stations such as the planned Axiom Station, which is due to send its first module to the ISS sometime in 2026. To exemplify the progress that’s been made towards growing plants in LRS, this study comes after researchers at the University of Florida successfully grew the plant, Arabidopsis thaliana, in lunar regolith while discovering the plants did not achieve desired parameters, which this most recent study has achieved.

2022 video discussing the University of Florida lunar regolith plant research

What new discoveries will researchers make about growing plants in lunar regolith, in materials from other worlds, in the coming years and decades? Only time will tell, and this is why we science!

As always, keep doing science & keep looking up!

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Well I consider that a success; the first aircraft on another world surpassed all expectations. Ingenuity, the helicopter that has been buzzing around on Mars has finally reached the end of its life after a total of 72 flights on the red planet. In a wonderful piece of computer imagery, Simeon Schmauß took a number of images of Ingeniuty from Perseverance and stiched them together into a mosaic and upscaled to provide a human eye view. 

The groundbreaking voyage of the Ingenuity helicopter commenced on February 18, 2021, upon its arrival on Mars. This journey was facilitated as part of the Mars 2020 mission, alongside the Perseverance rover. Ingenuity was developed by NASA’s Jet Propulsion Laboratory, with collaborative efforts from AeroVironment Inc., Qualcomm, SolAero, and Lockheed Space. Its primary objective was straightforward: to showcase the technological capabilities required for flight operations on an extraterrestrial terrain.

Once configured for flight, it stood at a height of 0.49 meters with a rotor span of 1.2 meters. While this may appear substantial in comparison to drones on Earth, such dimensions were imperative for achieving flight on Mars. The thinner atmosphere necessitated larger rotors to generate the required lift. These rotors were designed to rotate at a speed of 2,400 revolutions per minute, with two separate drives enabling the clockwise and counterclockwise rotation of blade sets. Positioned atop the rotors was a solar panel for battery charging, alongside a wireless communication system and essential navigation sensors and cameras.

The first flight took place on 19th April and sadly the 72nd flight on the 18th January was to be its last. An emergency landing led to damage to one of the rotor blades rendering Ingeniuty grounded, permanently. 

NASA’s Mars Perseverance rover acquired this image using its Left Mastcam-Z camera. Mastcam-Z is a pair of cameras located high on the rover’s mast. This image was acquired on Feb. 4, 2024 (Sol 1052) at the local mean solar time of 13:05:37. Image Credit: NASA/JPL-Caltech/ASU

One of the core principles of NASA is that the images and data they capture are all public domain and released for anyone to look at and work with. Taking six images from the right MastCam-Z of Perseverance, GeoVisual Design student Simeon Schmauß recreated the vista that a human visitor to Mars would have been greeted with. The image was even colour corrected to match our eyes and revealed Ingenuity’s final resting place among the rippling sands of Neretvav Vallis on Mars. 

The full resolution image really is incredible, testimony not only to the quality of the imaging platform on Perseverance but also to the processing skills of Schmauß. I found myself exploring the view for some time and even found myself transported to Mars (virtually of course) walking among the dunes on the Martian surface and coming across the plucky helicopter as it sat silently. Farewall Ingenuity, thank you for all the science and stunning images, you were an incredible helicoper and our first on another world. 

Source : Simeon Schmauß ‘X’ feed 

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I really don’t know how to introduce this article. Neutrinos are elementary particles and are electrically neutral. They are produced by numerous cosmological events. Trees, well, we all know what they are and in a recent paper, scientists believed it may be possible to use entire forests as neutrino detectors! I was a bit sceptical when I read the paper but its an interesting concept and certainly trees have been used as broadband antennae so perhaps, well its a fascinating concept.

Neutrinos have often been referred to as the ‘ghost particle’ due to their inability to interact with anything else. Despite this, they are one of the most common particles in the Universe with trillions passing through our bodies every single second! Unfortunately, their inability to interact with anything means that detecting them is rather challenging. 

The ultrahigh energy neutrinos rely upon huge volumes of water, air or ice to pick up any interactions. The larger the volume, the greater the chance of detection. In these detectors, they look for the decay of tau leptons (an elementary particle similar to the electron with negative electric charge) which are the result of a tau neutrino interaction. 

With any new detection array it is tricky to transition from the small proof of concept to full scale due to the sheer size required. The neutrino detector for example, known as Super-Kamiokande is a cylindrical tank containing 50,220 metric tons of pure water, 1,000 metre underground. Building something like this is a massive undertaking and in many cases, finding the location is problematic. 

The Super-Kamiokande experiment is located at the Kamioka Observatory, 1,000 m below ground in a mine near the Japanese city of Kamioka. Credit: Kamioka Observatory/ICRR/University of Tokyo

Some decaying tau decays via radio emissions require antennae for their detection. The array needs to be composed of thousands of manufactured antennae that have a clear line of sight to the horizon and must be distanced from civilisation to minimise potential interference. The practicality of manufacturing such an installation and the likely limited accessibility to the potential sites means there are difficult challenges to overcome. 

The paper recently published by S. Prohira from the University of Kansas discusses the potential for using forests as antennae. Trees have been used as far back as the Vietnam war which ended in 1975. Troops found themselves in the jungle and in need of a communication system without being able to lug around bulky equipment. Tree antennae were born. 

The ingenious forest antenna model has a number of advantages chiefly that the trees are sturdy and already established, saving effort and money on installation. Forests are also often found to contain a fairly uniform distribution of trees in locations that are usually already fairly barren granting clear views to the horizon. 

More testing is required but sensitively implemented, forest antennae systems could help preserve forests indeed may even help reforestation in areas where forests have been lost. Their implementation is a fairly simple task but must be completed with care to protect the trees. I confess, I started out cynical to this story but having researched it, think it’s a fascinating concept and one to watch over the months and years ahead.

Source : The Forest as a Neutrino Detector

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Galaxies experience a long strange trip through the cosmic web as they grow and evolve. It turns out that the neighborhoods they spend time in on the journey change their evolution, and that affects their star formation activity and alters their gas content.

Astronomer Gregory Rudnick of the University of Kansas has a grant to follow that galactic growth trail and figure out just how the trip alters the evolution of a galaxy. These giant stellar cities are spread throughout the Universe, said Rudnick, explaining that they tend to cluster together into large conglomerations. Hundreds of thousands of them group together in the largest ones, while smaller ones have only a few. In the grand scheme of things, they can also be part of the filamentary structure called the “cosmic web”. Or, some can be relatively isolated in “low-density” galactic neighborhoods.

How do they get clumped together, and what do they experience as they gather together? That’s what Rudnick and colleagues want to understand. “The primary objective of this project is to comprehend the impact of environmental factors on the transformation of galaxies,” he said.

The Process of Galaxy Evolution

How do these behemoths evolve and grow? A quick look at the history of our Milky Way gives us a good idea of the general story. It began forming as a cloud of hydrogen gas some 13 billion years ago. Gravity pushed the clouds together, which began the process of star formation. Other structures in the galaxy—the core, the flat disk, the halo—formed in quick succession. The infant Milky Way experienced multiple collisions with others throughout its history. It’s still cannibalizing some today. That’s more or less the “executive summary” of galactic growth.

Our Galaxy is part of a larger collection called the Local Group, which is itself part of the Virgo Supercluster. The Virgo collection is also part of a suspected larger grouping called Laniakea. And, all of this is part of the cosmic web that defines large-scale cosmic structure.

A mosaic of telescopic images showing the Virgo Supercluster. It’s part of the cosmic web in which a galaxy can exist during part of its evolution. Credit: NASA/Rogelio Bernal Andreo How the Trip Changes Galaxies

Rudner’s group plans to focus on the “superhighway” of filaments in the cosmic web, which connects the densest regions in the Universe. The team will focus on how galaxies react to the environment inside filaments as they get channeled into clusters. That trip seems to alter them as they traverse the web.

“Galaxies follow a path into these filaments, experiencing a dense environment for the first time before progressing into groups and clusters,” Rudnick said. “Studying galaxies in filaments allows us to examine the initial encounters of galaxies with dense environments. The majority of galaxies entering the ‘urban centers’ of clusters do so along these ‘superhighways,’ with only a minimal number taking rural routes that bring them into the clusters and groups without interacting much with their surroundings.”

A simulation of the “cosmic web” believed to connect galaxies. A galaxy can move into and out of this web throughout its lifetime. A void is visible in the center of the image, a spot where researchers found galaxy “tendrils.” Credit: Cunnama, Power, Newton and Cui (ICRAR). Tracing the Baryon Cycle

Rudner and his team want to see how conditions where galaxies congregate alter the gases in and around them. Filaments, fields, groups, and clusters all have different environments. Each of these neighborhoods affects gas behavior. Astronomers think of these changes in terms of a “baryon cycle”. That’s a complex phenomenon, actually. It describes all the ways that gas is processed in dense clusters and filaments of the cosmic web.

“The space between galaxies contains gas. Indeed, most of the atoms in the universe are in this gas, and that gas can accrete onto the galaxies,” Rudnick said. “This intergalactic gas undergoes a transformation into stars, although the efficiency of this process is relatively low, with only a small percentage contributing to star formation. The majority is expelled in the form of large winds.”

Think of galaxies as baryon processing engines, drawing gas from the intergalactic medium and converting some of it into stars. Stellar populations produce heavier elements as they evolve. Eventually all material ends up in space, along with the gas, forming a fountain that eventually falls back to the galaxy. When they move into a denser environment, the pressure of their passage disrupts the baryon cycle. It removes galactic gas or in some way deprives it of the “stuff” it needs to make new stars. This has happened in the centers of clusters. “The disruption affects the intake and expulsion of gas by galaxies, leading to alterations in their star formation processes,” Rudner said. “While there may be a temporary increase in star formation, in nearly all cases, it eventually results in a decline in star formation.”

Tracking Galaxies

For their work in tracing the long strange trips that galaxies take, Rudner and his team will comb through astronomical datasets from the DESI, WISE, and GALEX programs. This will give them access to some 14,000 galaxies to study. They’ll also get new images of galaxies to study. Students from the university, as well as selected high schools, will also take part in the study.

The grant funds a high school astronomy class affiliated with Siena College and extends a course already offered at Lawrence High School close to KU’s Lawrence campus. “These funds will extend the high school program’s longevity through 2026,” Rudnick said. “In collaboration with funds from KU, we were able to purchase 11 MacBook Pros for the school. Given that students only have iPads, which aren’t suitable for the research activities they needed to undertake, this grant facilitated the acquisition of computers that will enable their research.”

Ultimately, the extended team’s work should uncover more about the long-term evolution of galaxies, starting in the early Universe and extending to the modern cosmos. In addition, it will reveal more about the cosmic web and filaments that make up the large-scale structure that defines the Universe.

For More Information

Researchers Seek to Understand how Regions of “Cosmic Web” Influence Behavior of Galaxies

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We can’t see them directly, but we know they’re there. Supermassive black holes (SMBHs) likely dwell at the center of every large galaxy. Their overwhelming gravity draws material toward them, where it collects in an accretion disk, waiting its turn to cross the event horizon into oblivion.

But in one galaxy, the SMBH has choked on its meal and spit it out, sending material away at high speeds and clearing out the entire neighbourhood.

We’ve known there’s something at the heart of large galaxies since the early 1960s when astronomers discovered an unexplained radio source at the center of a giant elliptical galaxy. Astronomers thought it was a star, but its spectrum didn’t make sense. And since it was so far away, about 2.4 billion light-years distant, that meant it was emitting the energy of hundreds of galaxies. The rate of light emitted by the object varied, and the term quasar (quasi-stellar object) was created to describe it.

More quasars were discovered in the following years, and eventually, astronomers realized that gas falling into a massive compact object could create what they were seeing. More studies showed that the gas forms a rotating disk around the object, called an accretion disk. Astronomers also observed stars moving strangely near the center of galaxies, and only a massive object could explain their velocities and movement.

By the 1970s, astronomers thought that there was one of these massive objects at the Milky Way’s center. In 1974, astronomers discovered it and named it Sagitarrius A-star. Eventually, more and more evidence showed that most, if not all, large galaxies have SMBHs at their center. Now we understand the link between the accretion disk, the black hole, and active galactic nuclei (AGN), which are black holes that are actively consuming material and emitting lots of radiation.

So, this is our current picture of SMBHs. They’re massive compact objects that lurk at the centers of galaxies. They can have hundreds of millions, even billions, of solar masses. SMBHs draw material toward them, and the material collects in an accretion disk. The disk heats up and emits radiation, and tangled magnetic fields cause astrophysical jets to shoot out of the poles.

Artist’s impression of a supermassive black hole with a rotating accretion disk and astrophysical jets. Credit: NOIRLab/NSF/AURA/J. da Silva

Not all of the material in the accretion disk makes it past the event horizon. SMBHs only consume a fraction of the disk material. Once they reach the Eddington Limit, the rest is sent tumbling out into space, dragging some of the gas in the galactic centre with it.

Astronomers have spotted a distant SMBH in the galaxy Markarian 817 that has broken this picture. Beyond an SMBH’s accretion disk, neutral gas and dust form a torus. In the same region, clouds of interstellar star-forming gas reside just beyond the SMBH’s gravitational reach. The distant SMBH sent so much material from the disk out into space at high speed that it cleared out all of the gas in the region. That stifled star formation in the galactic centre.

The discovery is presented in new research in The Astrophysical Journal Letters. It’s titled “Fierce Feedback in an Obscured, Sub-Eddington State of the Seyfert 1.2 Markarian 817.” The lead author is Miranda Zak, an undergraduate researcher at the University of Michigan.

Astronomers have found SMBHs that are driving material away from their galactic centres before. They call this ‘black hole wind,’ and they’ve detected it around extremely bright accretion disks that have reached the limit for how much material they can accumulate. The black hole wind throws the excess material out into space.

But in Markarian 817, the disk is not very bright. That means it shouldn’t be at its Eddington Limit or mass accumulation limit. It’s only ‘snacking’ according to a press release announcing the discovery.

“You might expect very fast winds if a fan was turned on to its highest setting. In the galaxy we studied, called Markarian 817, the fan was turned on at a lower power setting, but there were still incredibly energetic winds being generated,” said study co-author Miranda Zak.

In scientific terms, these winds are called ultra-fast outflows (UFOs.) UFOs have velocities of many millions of miles per hour, and astronomers have found them coming from accretion disks that have reached their Eddington Limits. But this is different.

“UFOs are often detected at or above the Eddington limit; this result signals that black hole accretion has the potential to shape host galaxies even at modest Eddington fractions,” the authors write in their research.

Black hole accretion and the resulting UFOs can quench star formation near the galactic centre by blowing all of the gas away. The powerful wind also carries away the SMBH’s fuel, and without new gas to feed its accretion disk, it emits far less light.

“It is very uncommon to observe ultra-fast winds and even less common to detect winds that have enough energy to alter the character of their host galaxy. The fact that Markarian 817 produced these winds for around a year while not being in a particularly active state suggests that black holes may reshape their host galaxies much more than previously thought,” added co-author Elias Kammoun, an astronomer at the Roma Tre University in Italy.

Multiple telescopes and observatories contributed to this discovery. When material in an accretion disk heats up, it emits X-rays. However, when researchers observed Markarian 817 with NASA’s Swift observatory, the X-rays were nearly undetectable. “The X-ray signal was so faint that I was convinced I was doing something wrong!” exclaimed lead author Miranda Zak.

But Swift isn’t our best X-ray observatory. So, the astronomers turned to the ESA’s XMM-Newton X-ray observatory. Those observations showed that Markarian 817’s UFO was blocking out X-rays from the SMBH’s corona, the hole’s immediate surroundings. Another X-ray observatory, NASA’s NuSTAR telescope, confirmed those observations: the X-rays were there, just obscured.

The spectral ranges of the XMM-Newton and NuSTAR Telescopes. (Credits: NASA, ESA)

Markarian 817’s UFO only lasted about one year. But during that time, it reshaped the centre of the galaxy. This study shows in clear detail how black holes and their host galaxies shape each other and have powerful effects on each other’s evolution.

An artist’s illustration of Markarian 817 and the SMBH at its centre. Image Credit: ESA (acknowledgement: work performed by ATG under contract to ESA), CC BY-SA 3.0 IGO

The study also sheds light on why some galactic centres, the Milky Way’s included, don’t exhibit much active star formation. The SMBHs at their centres have blown away the star-forming gas. But this can only happen if the UFO is both powerful enough and long-lasting enough.

SMBH accretion and feedback, and how it shapes the galaxy that hosts it, is something astrophysicists are eager to learn more about. In this instance, the ESA’s XMM-Newton played a critical role in determining what was going on in Markarian 817.

The ESA launched the XMM-Newton observatory in 1999 to study interstellar X-ray sources. Image: ESA

Norbert Schartel is a project scientist for XMM-Newton. Though not a part of this research directly, Schartel spoke about how important XMM-Newton is to decipher what’s going on near SMBHs.

“Many outstanding problems in the study of black holes are a matter of achieving detections through long observations that stretch over many hours to catch important events. This highlights the prime importance of the XMM-Newton mission for the future. No other mission can deliver the combination of its high sensitivity and its ability to make long, uninterrupted observations,” said Schartel.

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Astronomers have many ways to measure the distance to galaxies billions of light years away, but most of them rely upon standard candles. These are astrophysical processes that have a brightness we can calibrate, such as Cepheid variable stars or Type Ia supernovae. Of course, all of these standard candles have some inherent variability, so astronomers also look for where our assumptions about them can lead us astray. As a case in point, a recent study in The Astrophysical Journal shows how galactic dust can bias distance observations.

The study compares two slightly different ways to measure galactic distances. The first method compares the X-ray luminosity of a galaxy to its brightness at ultraviolet wavelengths. Known as LX–LUV, this approach relies on the fact that active galactic nuclei (AGNs) have a similar spectrum depending on their overall brightness. The LX–LUV allows astronomers to determine the absolute magnitude, and therefore galactic distance. The second method is known as R – L and compares the ultraviolet luminosity of the accretion disk around the galaxy’s supermassive black hole with the radius of that accretion disk. The bigger the disk, the brighter it is, thus getting the absolute magnitude.

Both of these methods focus on the brightness of the AGN, and both involve UV brightness, so both methods should give us a similar distance. But often they don’t. The authors of this paper wanted to find out why, so they looked at 58 galaxies where both methods had been used to determine their distance. They then looked for factors that might skew the results of one method relative to the other.

The team found that dust within a galaxy can affect the LX–LUV method. Galactic dust, mostly made of carbon and silicon, can absorb X-ray light and re-emit other wavelengths. The more dusty a galaxy is, the more significantly it can skew the distance result. The team also found that the presence of dust doesn’t significantly bias the R – L method. Based on this, the authors recommend that the LX–LUV method not be used to measure galactic distances. That’s a little unfortunate since the R – L method is a bit more difficult to measure, but it means we can rule out data that could be skewing our cosmic distance measures. This could help us better understand the underlying issues of the Hubble tension, which continues to nag cosmologists.

The discovery of this bias doesn’t in any way undermine the standard model of cosmology, as these methods aren’t the only ones we can use to determine cosmic distances. Instead, it further improves our methods, so that we now have an even clearer understanding of how our Universe came to be.

Reference: Zaja?ek, Michal, et al. “Effect of Extinction on Quasar Luminosity Distances Determined from UV and X-Ray Flux Measurements.” The Astrophysical Journal 961.2 (2024): 229.

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Black holes have always held a special fascination for me ever since I was a geeky kid looking up at the stars. Their intense forces are the stuff of science fiction and can tear a star to pieces. This process is violent and can send bursts of electromagnetic radiation across the Cosmos. A paper recently published announces the discovery of 18 new tidal events just like this, doubling the number of identified shredded stars. 

Black holes are the remains of massive stars that have reached the end of their lives. During the main chunk of a stars life there are two forces at play; gravity trying to collapse a star and the thermonuclear force trying to force the star apart. When massive stars reach the end of their lives, gravity overcomes the thermonuclear force and the core collapses leading to the formation of a black hole. The intense gravity from a black hole can have a massive impact on the surrounding space not only warping space and time but also tearing apart any objects that wander too close. 

An artist’s illustration of a supermassive black hole (SMBH.) The SMBH in a distant galaxy expelled all the material in its accretion disk, clearing out a vast area. Image Credit: ESA

In the paper which was authored by Megan Masterson and team from MIT, appeared in the Astrophysical Journal and they announced the discovery of 18 new stellar graveyards where stars had been ripped up by the extreme gravity of a black hole. The event, known more properly as a Tidal Disruption Event (or TDE) gives off a burst of energy across the electromagnetic spectrum and it is this, the team has been hunting. 

Previously these events have been detected through observations in visual and x-ray radiation leading to the discovery of 12 TDE events. The MIT team did something a little more unusual though, they found events by searching for Infrared signals instead. Anytime a star is ripped up by a blackhole, bursts of radiation pour out in all directions and in dusty galaxies, the energy can be absorbed by the dust causing it to heat. As the dust heats up it emits infrared radiation and it is that, which has served as a signal of an embedded, unseen TDE. 

The team then searched through historical data looking at infrared observations and have now detected the closest TDE yet in the galaxy NGC7392 at a distance of 137 million light years. They continued to look through archive infrared data from NASAs Wide field Infrared Survey Explorer which has been searching for transient infrared events since 2009. Once they spotted a suspected TDE , they cross referenced the object with a catalog of all know nearby galaxies within 600 million light years. They detected about 1,000 events and traced the host galaxies. 

NEOWISE on the hunt. Credit: NASA/JPL

The source of the burst was then examined to see if it was something else like a burst of radiation from an active galactic nuclei or maybe a supernova explosion. Once these were ruled out, they analysed the signals looking for the tell tale signs of a TDE in the – a sharp pike followed by a gradual decline. 

Hunting for TDEs in infrared seems to have been immeasurably successful with not only gaining a greater understanding of the process leading to their formation but also in developing new techniques to help in their identification.

Source : Astronomers spot 18 black holes gobbling up nearby stars

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NASA’s Artemis mission objective is among other things, to get human beings back to the Moon. Much of the attention of late has been focussed on the rocket technology to get the astronauts there but as we progress from Artemis I to Artemis II – which aims to take a crew around the Moon and back before Artemis III lands them on the lunar surface – attention is shifting on the spacesuits the crew will wear. The new suits, built by Axiom Space are designed to provide the mobility and protection required on the surface and now, NASA has received samples and is testing them in simulated space environments. 

It’s been decades since human beings set foot on the Moon. For those like me that were not born in 1969, even the sight of the famous Armstrong footprint on the surface of the Moon still evokes so many emotions. Most of the technology from the Apollo days is decades old so NASA has commissioned Axiom Space to design and build new spacesuits. The suits were revealed during March 2023 and, instead of the usual Apollo trademark white the new Axiom suits sported a funky black and orange look although the suits delivered to NASA were classically white with blue and red stripes. 

Aldrin on the Moon. Astronaut Buzz Aldrin walks on the surface of the moon near the leg of the lunar module Eagle during the Apollo 11 mission. Mission commander Neil Armstrong took this photograph with a 70mm lunar surface camera. While astronauts Armstrong and Aldrin explored the Sea of Tranquility region of the moon, astronaut Michael Collins remained with the command and service modules in lunar orbit. Image Credit: NASA

The suits have a rather more funky name too; the Axiom Extravehicular Mobility Unit, or AxEMU for short. To arrive at the final design, Axiom worked closely with NASA experts who defined the technical and safety standards that the suit had to be built to. 

Having completed the design phase, it was straight into the test phase where the testers wore the new suits at the Johnson Space Centre test facility. Here they performed tests that would put the manoeuvring capability of the suits through their paces. Tasks included bending down to pick up lunar samples using geological tools – a task that sounds really easy but on the Moon with its thin atmosphere and minimal gravity coupled with the bulk of the space suit is far more difficult on the Moon.

The tests will go further though by submersing them, occupants and all into the Neutral Buoyancy Laboratory at NASA. This is ultimately just a large indoor swimming pool but is used to simulate the partial gravity. Together the two tests will explore any unseen limitations of the suits to enable final design tweaks to be worked upon. 

A diver tests out a spacesuit in NASA’s Neutral Buoyancy Laboratory in Houston in December 2014. Credit: Zugzwang5 (imgur)

The Axiom AxEMU suit has been developed to offer benefits with not just NASA in mind but for other space agencies and commercial space companies too. They offer a wider range of sizing adjustments to be able to accommodate the wider range of the public. Not only will it be suitable for more people, it will still offer the comfort and capability to support the tasks of the Artemis astronauts. 

Source : Axiom Space Tests Lunar Spacesuit at NASA’s Johnson Space Center

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One of contemporary astronomy’s most pressing questions concerns planet formation. We can see more deeply than ever into very young solar systems where planets are taking shape in the disks around young stars. But our view is still clouded by all the gas and dust in these young systems.

The picture of planet formation just got cloudier with the discovery that some young planets are shaped like flattened candies rather than spheres.

There are two main theories for planet formation, and they both start with stars.

Stars are born in giant molecular clouds of hydrogen. Due to natural variability in these clouds, dense cores of material form. As these cores gather more and more material, they eventually form a protostar. Protostars haven’t begun fusion yet, and they’re surrounded by gas and dust from their parent cloud. That reservoir of gas and dust is called a solar nebula.

As the protostar begins to rotate, the solar nebula begins to flatten out into a rotating disk. It’s called a protoplanetary disk, and this is where planets form according to two theorized processes.

This image is from ALMA, the Atacama Large Millimetre-submillimetre Array, and it shows the protoplanetary disk around a young star named HL Tauri. These ALMA observations reveal substructures within the disc that show the possible positions of planets forming in the dark patches within the system. As the planets gather mass, they ‘sweep’ lanes in the disk of matter, creating the dark gaps. It’s next to impossible to see actual planets forming. Image Credit: ALMA.

One of those processes is the core accretion theory. In core accretion, planetesimals form in the disk, and eventually, enough of them combine through collisions to form a rocky core. The rocky core continues to accrete more material from the disk through collisions. Once the core is massive enough, it can attract an atmosphere. Core accretion explains how rocky planets like Earth form as spheres.

But, the core accretion theory has limitations. It can’t explain how gas giants form because core accretion would take forever to manifest a planet like Jupiter. It also can’t explain moons well.

Instead, the disk fragmentation or disk instability theory explains how gas giants can form on wider orbits than terrestrial planets. Due to instabilities in the protoplanetary disk, massive planet-size clumps form quickly in the disk, and their gravity draws more material toward them. Over time, planets like Jupiter and Saturn form.

“This theory is appealing due to the fact that large planets can form very quickly at large distances from their host star, explaining some exoplanet observations,” said Fenton.

“We were very surprised that they turned out to be oblate spheroids, pretty similar to smarties.”

Research co-author Dimitris Stamatellos, University of Central Lancashire

A new research letter to be published in the journal Astronomy and Astrophysics presents evidence that young planets that form from disk instability aren’t spherical. Instead, they’re oblate spheroids shaped like flattened SmartiesTM. The research letter is titled “The 3D structure of disc-instability protoplanets,” and the authors are Adam Fenton and Dimitris Stamatellos. Fenton and Stamatellos are both from the Jeremiah Horrocks Institute for Mathematics, Physics, and Astronomy at the University of Central Lancashire.

“Many exoplanets, which are planets that orbit stars in other solar systems outside of our own, have been discovered in the last three decades,” Fenton said in a press release accompanying the research. “Despite observing many thousands of them, how they form remains unexplained.”

Explaining how planets form by observing them is extremely difficult. Young planets are shrouded by the gas and dust in the disk. In this research, the pair used a supercomputer to perform advanced simulations of wide-orbit planets forming via the disk instability process.

This image is a snapshot from the simulations. The colour scale shows the density of the material. The disk has become unstable and fragmented, and clumps of material are forming. These clumps represent planets. Image Credit: Fenton and Stamatellos 2024.

The researchers focused on the shapes young planets take and how they can grow into massive behemoths like Jupiter. In their simulations, they varied things like disk temperature and gas density.

“It was an extremely demanding computational project requiring half a million CPU hours on the UK’s DiRAC High-Performance Computing Facility,” Fenton said. “But the results were amazing and worth the effort.”

The most surprising result of the simulations is that planets forming due to disk instability take the shape of Smarties, oblate spheroids.

“We have been studying planet formation for a long time, but never before had we thought to check the shape of the planets as they form in the simulations,” said co-author Dimitris Stamatellos. “We had always assumed that they were spherical.”

“We were very surprised that they turned out to be oblate spheroids, pretty similar to smarties.”

Overall, the simulation results showed that the 3D structure of exoplanets that form via instability is shaped by their environment in the disk. Interactions with a galaxy’s spiral arms and even past merger events can contribute to the shape, especially the outer regions of the exoplanets. But most were oblate spheroids, regardless. “The large majority of the protoplanets that form in the simulations are oblate spheroids rather than spherical, and they accrete faster from their poles,” the researchers explain.

This figure from the research shows the velocity vectors of gas accreting onto the planet. The arrows show the direction, and the length of the tail shows the velocity. Longer tails indicate higher velocities. The simulations show that planets forming via disk instability and fragmentation accrete gas from the polar directions. Colour indicates gas density. Image Credit: Fenton and Stamatellos 2024.

When it comes to directly observing exoplanets as they form, we’ve got a while to wait. Upcoming telescopes like the Giant Magellan Telescope and the European Extremely Large Telescope (E-ELT) will bring us closer to seeing exoplanets in detail. The E-ELT is touted as being able to see individual, large exoplanets. The first light for these telescopes is several years away.

These simulations show that the viewing angle can be key. From the top, these planets appear as spheres, but from the side, their oblate nature becomes clear. From the wrong angle, it’s possible to misunderstand the planet formation process.

“The 3D structure of disc-instability protoplanets is expected to affect their observed properties and should be taken into account when interpreting observations of protoplanets embedded in their parent discs,” the authors write.

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Although the U.S. Space Force is tasked with military operations in regards to space, they’ve never actually sent one of their own into orbit. This week, the agency announced that Col. Nick Hague will launch to the International Space Station in August 2024 to pilot the Crew-9 mission, as part of SpaceX’s ninth crew rotation to the ISS for NASA. He’ll join two NASA astronauts and a cosmonaut on the trip to space and then work as a flight engineer, spending six months on the station doing research and operations activities.

“The core of our mission on the space station is to perform science experiments and collect data,” Hague said in a U.S. Space Force news release. “The International Space Station provides a unique platform in microgravity, which allows researchers from around the world to explore and discover processes that could have significant impact on the behavior of our bodies and the environment around us both on Earth and off planet.”

While this is Hague’s first flight to space as a Guardian, its not his first rodeo in space – and he certainly has some exciting tales to tell. He’s launched twice before as a NASA astronaut, but actually only made it to space once.

During his first flight, Hague and Russian cosmonaut Alexey Ovchinin launched on board a Soyuz from Russia’s Baikonur Cosmodrome in Kazakhstan, but the flight had to be aborted when the Soyuz-FG rocket experienced an anomaly just minutes after liftoff.

The Soyuz spacecraft was thrown clear of the rocket and plunged back to Earth for a ballistic landing. Experts estimate Hague and Ovchinin experienced 6 to 7 G’s during the nail-biting descent. It took the search and rescue team awhile to find the crew, but eventually they were located and found to be in good condition.  

Expedition 57 Flight Engineer Alexey Ovchinin of Roscosmos, left, and Flight Engineer Nick Hague of NASA, right. embrace their families after landing at the Krayniy Airport, Thursday, Oct. 11, 2018 in Baikonur, Kazakhstan. Hague and Ovchinin arrived from Zhezkazgan after Russian Search and Rescue teams brought them from the Soyuz landing site. During the Soyuz MS-10 spacecraft’s climb to orbit, an anomaly occurred, resulting in an abort downrange. The crew was recovered in good condition. Photo Credit: NASA/Bill Ingalls.

Just five months later—in March 2019—Hague and Ovchinin launched again, along with crewmate NASA astronaut Christina Hammock Koch, and this time made it with no hiccups to the International Space Station. Hague completed a 203-day mission, conducting three spacewalks, totaling 19 hours and 56 minutes, and he also participated in hundreds of experiments in biology, biotechnology, physical science and Earth science.

After returning from his mission in 2019, Hague transitioned to the Pentagon for a leadership role with the newly developed Space Force as its Director of Test and Evaluation. In 2021, while serving in this role, he transferred from the Air Force to Space Force.

Hague joins the crew of Mission Specialist Stephanie Wilson, Roscomos cosmonaut and Mission Specialist Aleksandr Gorbunov, U.S. Space Force Col. Nick Hague and Commander Zena Cardman.

“Being a part of this mission is a unique honor, but it’s truly a collective effort,” Hague said. “Guardians worldwide ensure safe and secure operations of critical systems for launch and on station. From GPS satellites that underpin our station navigation systems, to space domain awareness sites around the globe that help NASA prevent orbital debris from colliding with the space station, to the launch range that my crew will use when we liftoff, Guardians provide critical support without which our NASA human spaceflight program wouldn’t be possible.”

Hague said during his mission, he will represent approximately 14,000 military and civilian Guardians who continue to support NASA and commercial missions in, from, and to space.

Official NASA SpaceX Crew-9 portrait of Mission Specialist Stephanie Wilson, Roscomos cosmonaut Mission Specialist Aleksandr Gorbunov, U.S. Space Force Col. Nick Hague and Commander Zena Cardman. Credit: NASA.

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If you want to determine your mass, it’s pretty easy. Just step on a scale and look at the number it gives you. That number tells you the gravitational pull of Earth upon you, so if you feel the number is too high, take comfort that Earth just finds you more attractive than others. The same scale could also be used to measure the mass of Earth. If you place a kilogram mass on the scale, the weight it gives is also the weight of Earth in the gravitational field of the kilogram. With a bit of mass, you have the mass of Earth.

Things aren’t quite that simple. The Earth is not a perfectly spherical, perfectly uniform mass, so its gravitational pull varies slightly across the globe. But this method gives a reasonable ballpark value, and we can use it to estimate the masses of other objects in the solar system. But how can we determine the mass of something larger, such as the Milky Way? One method is to estimate the number of stars in the galaxy and their masses, then estimate the mass of all the interstellar gas and dust, and then rough out the amount of dark matter… It all gets very complicated.

A better way is to look at how the orbital speed of stars varies with distance from the galactic center. This is known as the rotation curve and gives an upper mass limit on the Milky Way, which seems to be around 600 billion to a trillion solar masses. The wide uncertainty gives you an idea of just how difficult it is to measure our galaxy’s mass. But a new study introduces a new method, and it could help astronomers pin things down.

Estimated escape velocities at different galactic radii. Credit: Roche, et al

The method looks at the escape velocity of stars in our galaxy. If a star is moving fast enough, it can overcome the gravitational pull of the Milky Way and escape into interstellar space. The minimum speed necessary to escape depends upon our galaxy’s mass, so measuring one gives you the other. Unfortunately, only a handful of stars are known to be escaping, which is not enough to get a good handle on galactic mass. So the team looked at the statistical distribution of stellar speeds as measured by the Gaia spacecraft.

The method is similar to weighing the Moon with a handful of dust. If you were standing on the Moon and tossed dust upward, the slower-moving dust particles would reach a lower height than faster particles. If you measured the speeds and positions of the dust particles, the statistical relation between speed and height would tell you how strongly the Moon pulls on the motes, and thus the mass of the Moon. It would be easier just to bring our kilogram and scale to measure lunar mass, but the dust method could work.

In the Milky Way, the stars are like dustmotes, swirling around in the gravitational field of the galaxy. The team used the speeds and positions of a billion stars to estimate the escape velocity at different distances from the galactic center. From that, they could determine the overall mass of the Milky Way. They calculated a mass of 640 billion Suns.

This is on the lower end of earlier estimates, and if accurate it means that the Milky Way has a bit less dark matter than we thought.

Reference: Roche, Cian, et al. “The Escape Velocity Profile of the Milky Way from Gaia DR3.” arXiv preprint arXiv:2402.00108 (2024).

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The Juno spacecraft has revealed some fascinating things about Jupiter since it began exploring the system on July 4th, 2016. Not only is it the first robotic mission to study Jupiter up close while orbiting it since the Galileo spacecraft, which studied the gas giant and its satellites from 1995 to 2003. Juno is also the first robotic explorer to look below Jupiter’s dense clouds to investigate the planet’s magnetic field, composition, and structure. The data this has produced is helping scientists address questions about how Jupiter formed and the origins of the Solar System.

Since 2021, the probe has been in an extended mission phase, where it has been making flybys of some of Jupiter’s largest moons, including Ganymede, Europa, and Io. As it passes these satellites, Juno has captured some incredible images with its main imaging instrument, the JunoCam. On Saturday, February 3rd, 2024, the Juno spacecraft made another flyby of Io and took more captivating photos of the volcanic moon and its pockmarked surface. This was the second part of a twin flyby designed to provide new insight into Io’s volcanic nature and the interior structure of the satellite.

The previous flyby occurred on December 30th, 2023, and (like this latest flyby) brought the spacecraft within 1,500 km (930 mi) of Io’s surface. The two flybys are the closest that any spacecraft has ever made of Io, breaking the previous record established by Juno during the flyby that occurred on October 15th, 2023, where the probe reached a minimum distance of 12,000 km (mi) from the moon’s surface. No spacecraft has passed this close to Io since the Galileo mission buzzed the volcanic moon over twenty years ago.

Image of Io taken by the JunoCam on Dec. 30th, 2023, and processed by citizen scientist Emma Wälimäki. Credit: NASA/JPL-Caltech/SwRI/MSSS/Emma Wälimäki © CC BY

As always, raw images captured during flybys are available on the mission’s Southwest Research Institute (SwRI) website, where people can upload, process, and colorize them. One particular image processed by citizen scientist Emma Wälimäki (see above) shows the moon’s dark side was lit by sunlight reflected by Jupiter (aka. “Jupitershine”). Other images provided by Juno include the many infrared images that show the many active volcanoes on the moon’s surface and even eruptions that were visible during flybys because they occurred on the moon’s dark side.

These images are part of an investigation by scientists to determine if Io’s active volcanoes are powered by a global magma ocean beneath its surface. Based on current geological models, scientists believe this magma ocean results from tidal flexing in Io’s interior caused by interactions with Jupiter’s powerful gravity. This is similar to what Europa and other icy satellites are believed to experience, where tidal flexing leads to hydrothermal activity at the core-mantle boundary that maintains oceans of liquid water in the interior.

As of this article’s publication, the Juno mission has operated for twelve years, five months, and twenty-seven days. Per its mission extension, the probe will continue to orbit Jupiter from pole to pole until September 2025, though this could be extended further. As long as Juno’s solar panel wings (the largest ever deployed) continue providing power, the mission will continue to study the system and address the fundamental questions of how Jupiter and its satellites came to be.

More images are available at the Juno mission website at the Southwest Research Institute (SwRI).

Further Reading: Mission Juno SwRI

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