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Humanity got its first look at the other side of the Moon in 1959 when the USSR’s Luna 3 probe captured our first images of the Lunar far side. The pictures were shocking, pointing out a pronounced difference between the Moon’s different sides. Now China is sending another lander to the far side.

This time, it’ll bring back a sample from this long-unseen domain that could explain the puzzling difference.

Chang’e-6 (CE-6) launched on May 3rd and is headed for the second largest impact crater in the Solar System: the South Pole Aitken (SPA) basin. It’ll land at Apollo Basin, a sub-basin inside the much larger SPA basin.

China has placed a lander on the far side of the Moon before (Chang’e 4.) They also placed a lander on the near side of the Moon and brought back samples (Chang’e 5.) But CE-6 will be the first sample ever returned from the Lunar far side. It’s the latest mission in the Chinese Lunar Exploration Program (CLEP.)

This graphic outlines China’s Lunar Exploration Program. Image Credit: CASC

A new paper published in Earth and Planetary Science Letters outlines the significance of the CE-6 landing site and the samples it’ll return to Earth. It’s titled “Long-lasting farside volcanism in the Apollo basin: Chang’e-6 landing site.” The lead author is Dr. Yuqi Qian from the Department of Earth Sciences at The University of Hong Kong.

When the USSR’s Luna 3 probe gave us our first look at the lunar far side, it didn’t take scientists long to realize how different it is from the near side. The near side of the Moon is marked by vast basaltic lava plains called lunar mares. Mares cover about 31% of the lunar near side.

But the far side is much different. Lunar mares cover only about 2% of the lunar far side. Instead, it’s dominated by densely-cratered highlands. This is known as the lunar dichotomy. The difference likely stems from a deposit of heat-producing elements under the near side that created the lunar mares. Scientists have also proposed that a long-gone companion moon slammed into the far side, creating the highlands.

This global map of the Moon, as seen from the Clementine mission, shows the differences between the lunar near side and far side. The familiar near side is marked by dark lunar mares. The far side has very few of them. This is known as the lunar dichotomy. Credit: NASA.

“A major lunar scientific question is the cause of the paucity of farside mare basalts,” Qian and his colleagues write in their paper. “The Chang’e-6 (CE-6) mission, the first sample-return mission to the lunar farside, is targeted to land in the southern Apollo basin, sampling farside mare basalts with critical insights into early lunar evolution.” 

CE-6 samples from the far side can start to answer the questions about the differences between the two sides. In preparation for receiving the samples, Qian and his colleagues studied the Apollo Basin’s volcanism. Their work revealed diverse and puzzling volcanism.

Their research shows that the Apollo basin experienced volcanic activities lasting from the Nectarian (~4.05 billion years ago) to the Eratosthenian Period (~1.79 billion years ago). However, since the far side’s crust is much thicker, it influenced the volcanic activity. In regions like the Oppenheimer Crater, where the crust has intermediate thickness, lava dikes stall beneath the crater floor. Lava spreads laterally and forms a sill and floor-fractured crater.

These two images give context to the CE-6 landing site. The left image shows where Apollo is inside the SPA. The right image shows some of the features in the Apollo crater, with the landing zone in a white rectangle. Image Credit: Qian et al. 2024.

Some regions, like the inner floor of the Apollo crater, have thin crusts. Here, lava dikes erupted directly and formed extensive lava flows. But where the crust is thickest, in the highland regions, there’s no evidence that dikes there ever reach the surface.

“This fundamental finding indicates that the crustal thickness discrepancy between near side and far side may be the primary cause of lunar asymmetrical volcanism,” said Dr. Qian. “This can be tested by the returned Chang’e-6 samples.”

They’ve chosen Apollo Crater’s Southern Mare partly because it contains at least two historic eruptions from two different times. Each one has a different Titanium content. The earlier one occurred ~3.34 billion years ago and has a low Titanium content (3.2% by weight.) The later one occurred ~3.07 billion years ago and has a higher Titanium content (6.2% by weight.)

This figure from the study shows the prime location for collecting samples according to the authors. This region would provide samples from the older, low-Ti basalts, the younger high-Ti basalts, and also overlying impact ejecta from the Chaffee S crater. Image Credit: Qian et al. 2024.

The titanium content in the rock is relevant because of petrogenesis, the origin and formation of rocks. Scientists think that high-Ti and low-Ti lunar basalts form when different geological layers of the Moon melted. “CE-6 samples returned from the unique geological setting will provide significant petrogenetic information to address further the paucity of farside mare basalts and the lunar nearside-farside dichotomy,” the authors write.

The authors suggest that CE-6 collect samples from the edge of the later eruption with the higher Titanium content. That sample will have higher scientific value because it’ll actually sample three things at once: Newer high-Ti basalt, underlying low-Ti basalt, and other materials unrelated to the mares that were transported by impact events. “Diverse sample sources would provide important insights into solving a series of lunar scientific questions hidden in the Apollo basin,” said Professor Joseph Michalski, a co-author of the paper also from the University of Hong Kong.

“The result of our research is a great contribution to the Chang’e-6 lunar mission. It sets a geological framework for completely understanding the soon-returned Chang’e-6 samples and will be a key reference for the upcoming sample analysis for Chinese scientists,” said Professor Guochun Zhao, Chair Professor of HKU Department of Earth Sciences and the co-author of the paper.

Chang’e 6 will deliver up to 2 kg (4.4 lbs) of lunar material. It should arrive on Earth around June 25th.

“These returned samples could help to answer questions about the evolution of high-Ti and low-Ti basalts, the influence of crustal thickness on lunar volcanism, and the most fundamental unsolved question of lunar science: What is the cause of the pronounced lunar nearside-farside asymmetry?” the authors conclude.

The post Here’s Where China’s Sample Return Mission is Headed appeared first on Universe Today.

Ultra-fast pulses of laser light can be shaped into vortices similar to smoke rings – when chained together, they can carry enough information to transmit a simple image

A rare geomagnetic storm not seen for nearly 20 years could cause a stunning aurora borealis on 10 and 11 May

As often as four days a week, Boeing EA-18G Growler electronic attack aircraft based at Naval Air Station Whidbey Island fly loops overhead as pilots practice touch-and-go landings. The noise is immense. New research shows that the noise isn't just disruptive -- it presents a substantial risk to public health.

Exoplanets are a fascinating astronomy topic, especially the so-called “Hot Jupiters”. They’re overheated massive worlds often found orbiting very close to their stars—hence the name. Extreme gravitational interactions can tug them right into their stars over millions of years. However, some hot Jupiters appear to be spiraling in faster than gravity can explain.

WASP-12b is a good example of one of these rapidly spiraling hot Jupiters. In about three million years, thanks to orbital decay, it will become one with its yellow dwarf host star. Both are part of a triple-star system containing two red dwarf stars. The hot Jupiter orbits the dwarf in just over one Earth day at a distance of about 3.5 million kilometers. That’s well within the orbit of Mercury around the Sun. Thanks to that orbit and gravitational influence, one side of the planet always faces the star. That heats only one side and puts the surface temperature at about 2,200 C. Eventually heat flows to the opposite side, which stirs up strong winds in the upper atmosphere. The planet doesn’t reflect much light, and astronomers have described it as a pitch-black world.

As if all that isn’t odd enough, the gravitational pull of the nearby star distorts this hot Jupiter into an egglike shape. It’s also stripping the planet’s atmosphere away. So, it’s no wonder astronomers described WASP-12b as a doomed planet.

Artist’s impression of WASP-12b, a Hot Jupiter deformed by its close orbit to its star. Credit: NASA What’s Tugging on Hot Jupiters?

According to conventional theory, a hot Jupiter planet like WASP-12b should create strong gravitational tidal waves between themselves and their parent stars. Those waves transfer energy, which tugs at the planet. That pulls the planet right into the star. Such a fiery death is definitely in WASP-12b’s future. But, there’s just one problem: it’s getting sucked in faster than gravitational tidal waves can explain. What’s happening?

A team of scientists at Durham University in England studied WASP-12b and they’ve come up with an interesting idea. What if this hot Jupiter’s fate is determined by magnetic fields? That’s what Durham’s Craig Duguid proposed in a recently published paper. Duguid’s team thinks the strong magnetic fields inside some stars can dissipate the tidal waves generated by orbiting hot Jupiters.

Artist’s concept of the exoplanet WASP-12b, parent star devouring its hot Jupiter planet. Artwork Credit: NASA, ESA, and G. Bacon (STScI)

How this works isn’t completely confirmed yet, but here’s the basic idea. Inwardly propagating internal gravity waves (IGWs) (such as those from the nearby hot Jupiter) move through a star. They eventually run into the star’s magnetic interior. If that magnetic field is strong enough, it transforms them into magnetic waves. They move back outward and eventually dissipate. In the process, however, that dissipation causes a huge energy drain. The result is still the same as with gravitational tidal waves: the hot Jupiter loses energy and plows into its parent star. And, it could explain why some hot Jupiters spiral into their stars more quickly than expected.

Exploring the Magnetic Mechanism Idea

In the paper, Duguid and his team used models of stars with convective cores—such as F-type stars with masses between 1.2 to 1.6 solar masses. Astronomers suspect these experience weak tidal dissipation. The team used the known properties of these stars’ interiors, along with estimates of their magnetic fields. For these stars, a convective core is the dynamo that generates the magnetic field. Although it’s classified as a type-G star, WASP-12 fits into the study, thanks to its near-solar mass and radius.

So, is it just gravitational tidal waves pulling the planet in, or could the proposed magnetic field action be at work? Duguid and colleagues concluded that the magnetic field idea is very possible. They write, “Our main result is that this previously unexplored source of efficient tidal dissipation can operate in stars within this mass range for significant fractions of their lifetimes. This tidal dissipation mechanism appears to be consistent with the observed inspiral of WASP-12b and more generally could play an important role in the orbital evolution of hot Jupiters—and to lower-mass ultra-short-period planets—orbiting F-type stars.”

Need More Data about Hot Jupiters

It’s an interesting result. There are a great many hot Jupiters in the exoplanet archives, simply because they are the easiest exoplanets to observe. Some of them are spiraling in faster than expected. This leads the authors to suggest that additional studies of similar-type stars and their hot Jupiters could confirm the magnetic mechanism. In addition, future observations could help astronomers also understand the tidal wave theory and help place some constraints on the types of stars where it would operate.

For More Information

Scientists Explain Why Some Exoplanets are Spiraling Towards Their Stars
An Efficient Tidal Dissipation Mechanism via Stellar Magnetic Fields

The post Why Hot Jupiters Spiral into Their Stars appeared first on Universe Today.

The Large and Small Magellanic Clouds are well known satellite galaxies of the Milky Way but there are more. It is surrounded by at least 61 within 1.4 million light years (for context the Andromeda Galaxy is 2.5 million light years away) but there are likely to be more. A team of astronomers have been hunting for more companions using the Subaru telescope and so far, have searched just 3% of the sky. To everyone’s surprise they have found nine previously undiscovered satellite galaxies, far more than expected. 

Data from Gaia (the satellite collecting accurate position information of astronomical objects) suggests that most of the satellite galaxies orbiting our own are newcomers! Even the Large and Small Magellanic Clouds are now known to be newcomers. Whether any of these will fall into orbit around the Milky Way is as yet unknown, largely because we do not have an accurate measure for the mass of our home Galaxy.

The recent search hopes to expand our understanding of this corner of the Universe with the first detailed search for companion dwarf galaxies. The paper from lead author Daisuke Homma and team from the National Astronomical Observatory of Japan reports on the findings of their survey using the Subaru Telescope. 

Based on Mauna Kea in Hawaii The Subaru Telescope is an 8.2m diameter telescope located at the Mauna Kea Observatory in Hawaii. Until 2005 it was the largest single mirror telescope in the world with a gigantic 8.2 metre mirror. In all telescopes, larger mirrors collect more light bringing with it the ability to see fainter objects and finer levels of detail. A number of telescopes have now surpassed Subaru’s massive light collecting power but multi-mirror telescopes are becoming more popular. 

As the cornerstone of the study is a drive to understand dark matter distribution. The concept of the Universe being dominated by cold dark matter nicely describes the large scale model of the cosmos. It struggles however, to describe the structure in the local Universe predicting hundreds of satellite galaxies to the Milky Way. Until recently, we only knew of a handful of satellite galaxies contradicting the model in a quandary known as the missing satellites problem. The team from Japan hopes their work will help provide clues to understand this problem.

The paper reports that the previous data obtained before 2018 of an area of sky covering 676 degrees2 revealed three candidate satellite galaxies; Vir I, Cet III and Boo IV. Data released over the three years that followed covering 1,140 degrees2 revealed two additional candidates; Sext II and Vir III. Unexpectedly, the model suggests there should be  3.9 ± 0.9 satellite galaxies within 10 pc within the virial radius of the Milky Way (based on the density distribution of the Milky Way). Instead the team found more, nine to be precise! It seemed then that the missing satellite problem was no worse than expected, indeed there were too many galaxies!

The team acknowledged that their research was based on statistically small numbers and several assumptions had been made based on an isotropic distribution of satellites. To progress this further, there will need to be follow up studies of stars in the satellite galaxies and high resolution imaging.

Source : Final Results of Search for New Milky Way Satellites in the Hyper Suprime-Cam Subaru Strategic Program Survey: Discovery of Two More Candidates

The post Does the Milky Way Have Too Many Satellite Galaxies? appeared first on Universe Today.

Many artificial intelligence (AI) systems have already learned how to deceive humans, even systems that have been trained to be helpful and honest. Researchers describe the risks of deception by AI systems and call for governments to develop strong regulations to address this issue as soon as possible.

Astronomers have proposed a new theory to explain the origin of phosphorus, one of the elements important for life on Earth. The theory suggests a type of stellar explosion known as ONe novae as a major source of phosphorus.

A new approach to transport ticketing offers a step towards an integrated, transparent system that works efficiently for both ticket providers and passengers across all modes of transport.

A new approach to transport ticketing offers a step towards an integrated, transparent system that works efficiently for both ticket providers and passengers across all modes of transport.

Employers are significantly more likely to offer job interviews and higher salaries to graduates with experience of artificial intelligence, according to new research.

Employers are significantly more likely to offer job interviews and higher salaries to graduates with experience of artificial intelligence, according to new research.

Sufficiently advanced aliens would be able to capture vast quantities of energy from their star using a massive structure called a Dyson sphere. Such a device would give off an infrared heat signature - and astronomers have just spotted 60 stars that seem to match

I discuss the war in the Middle East with Malgorzata a lot and, like  Roseanne Roseannadanna, I ask a lot of questions. Andrzej had written a precis of his view of what’s going on there for Listy, and Malgorzata translated his Polish into English just for my sake. I thought I’d post Andrzej’s take on this site, but if you read Polish, you can see the original on Listy here.  (Yahya Sinwar is of course the leader of Hamas.)

As you can see, Andrzej is incensed at Biden’s decision to withhold arms from Israel and sees this as a sign that Biden is concerned more with his own reelection and with achieving comity with Iran than with defeating the terrorism of Hamas. Remember, these are Andrzej’s views, not mine, but I have to say there’s substantial (though not complete) overlap

Biden-Sinwar-Khamenei Pact

Andrzej Koraszewski

The former U.S. ambassador to Israel said there was no doubt that Biden had sided with Hamas. On Holocaust Remembrance Day, the American President announced that he intends to stop supplying weapons to Israel (with the exception of missiles for the Iron Dome). In other words, the American President announced that he would try to avoid too many Jewish casualties, but eliminating the threat to Israeli civilians interferes with his plans to cooperate with Iran.

According to The New York Times, this is a “turning point”. We are actually seeing a qualitative change. Biden said out loud what he had quietly said for days. Restrictions on American arms and ammunition supplies had actually begun earlier, although there were official attempts to deny this. Now, on Holocaust Remembrance Day, the American president, citing concern for the Palestinian civilian population, decided that he must save Hamas from final defeat and create the conditions for the creation of a Palestinian state under Hamas.

We hear that it is still just a threat, that supplies will be halted “if,” but the Pentagon confirms that they have already been halted.

Is the American president naïve, or is he just pretending that he does not know what he is demanding? In all the months since Hamas started the war, American condemnations of Hamas have been nothing but empty words. There has been no firm pressure on Qatar or Iran, no demand for the expulsion of Hamas leaders from Qatar, no demand for the immediate release of Israeli hostages, no threats to move the U.S. military base out of Qatar, and no ultimatum to Tehran. On the contrary, all the American grievances were directed at Israel, Hamas’s information about Israel’s alleged crimes was taken seriously, human rights were turned into a laughing stock, a tool for constantly accusing Jews, no one blamed “President” Abbas for supporting Hamas’s barbarism, and the American administration gave permission for public hatred of the Jewish state.

The U.S. President has previously asserted that “Hamas does not represent the Palestinians.” He did not reveal the secret of how he knew this, and he also pretended that he had no knowledge of Palestinian opinion polls, or who supposedly represented these Palestinians and how they did it.

Meanwhile, Tehran said on the same day that it may be “forced to change its nuclear doctrine and build nuclear bombs if its existence is threatened.” The fact that Iran either already has nuclear weapons or is a few weeks away from building them has been known for some time. Now they have apparently decided that they have gotten green light from Washington and it is time to stop pretending that they are not aiming at acquiring nuclear weapons at all. Thus, there is no longer a need for a fatwa (which President Obama happily talked about, but which no one has ever seen), which supposedly stated that Islam forbids the production of nuclear weapons.

The new UN statements on readiness to recognize the “State of Palestine” were probably not related to President Biden’s statement on Holocaust Remembrance Day, but it is easy to guess that the atmosphere was already considered favorable for taking this step, because there is a possibility that the US in the Security Council will not block the proposal, and the General Assembly resolution itself will certainly obtain the required majority, so journalists will consider it a binding decision of the UN anyway, and that’s what it’s all about.

So what does this “turning point” for America mean? Israeli historian Gadi Taub, in an article published on the same day, wrote:

In the eyes of the Biden administration Hamas is the smaller problem. The bigger problem is Benjamin Netanyahu. The U.S. is willing to live with Iran’s proxies everywhere, as part of its “regional integration” policy—i.e., appeasing Iran. But they are unwilling to live with Benjamin Netanyahu’s coalition. The stubborn Netanyahu clearly does not want to learn from his would-be tutors like U.S. Secretary of State Anthony Blinken how to “share the neighborhood” with genocidaires in Gaza, Judea and Samaria, Lebanon, and Tehran, whom his electorate understands to be bent on murdering them.

Tony Bardan, an American scientist from the Center for Research on Terrorism of the Foundation for the Defense of Democracies, recently wrote that Israel is facing a choice whether to remain an independent state or to be a client-oriented country in the service of a great power. Bardan reminds us that the latter has already happened once. Herod the Great was practically the governor of Rome, and it ended with the destruction of the temple, and in the following decades the genocide of the Jews and the exile of most of the survivors.

Gadi Taub, describing today’s American frolics in the Middle East—insidious attempts to overthrow the elected leader of the Israeli government and then collusion with a possible “U.S. own” Israeli prime minister—shows that for the Democratic Party, the enemy is Netanyahu rather than Islamic terrorism (not seen as a threat to America and the entire democratic world) and rather than another nuclear-armed enemy of democracy nor a genocidal Hamas.

The American president repeated his usual mantras about Israel’s right to defend itself and about his steadfast support for its ally, while doing everything in his power to save Israel’s genocidal enemy and strengthen its main sponsor.

In a world that has returned to the old rut of murderous Jew-hatred, Israel is dependent on American aid and care. But, Taub writes, the United States keeps Israel on a leash, rationing ammunition, forcing it to uncontrollably deliver humanitarian aid that falls into the hands of Hamas, maintaining its power over the people of Gaza, and in the diplomatic field supporting unilateral recognition of a Palestinian state. And while the U.S. helped repel a massive rocket attack by Iran, it forced only a symbolic response from Israel. America’s primary goal today is to ensure the survival of Hamas as ruler of the Gazan fortress.

The United States treats Israel as Jews have always been treated – with superiority and contempt. They invited the prime minister’s political rival (Gantz) to the talks, tried to summon the commander-in-chief of the Israeli army for separate talks, and did not protest when a caricature of an international court threatens to issue an arrest warrant for Israeli leaders. Moreover, there is a great deal of evidence pointing to U.S. government financial and organizational support for Israel’s internal divisions and political destabilization of the country at a time of struggle for existential survival.

Let’s not kid ourselves, the “turning point” is just the climax. Even if not everything is going according to plan and Benny Gantz has not yet decided to cooperate fully, and Prime Minister Netanyahu apparently refuses to give in to pressure, the American alliance with Hamas is delaying the final defeat of this terrorist organization. And the campaign of relentlessly dishonest accusations against Israel is intensifying with each passing day the hostility towards the Jewish state, hostility towards Jews, and sympathy for enemies not only of Israel, but also of America and the rest of the democratic world.

The intentions of the allies are clear: the poster of the BDS movement says it bluntly:

NOTE: A commenter below points out that this is not from the BDS movement, but from an anarchist site. So ignore the figure below.

For Islamists, Hamas’s war with Israel is intended only to open the gate to further fighting. For President Biden, only his election campaign and the expectations of his electorate are important. The option to support the Islamic Republic of Iran was chosen by President Obama, and Biden probably really believes that Israel should learn to live with a Palestinian state armed by Iran and with Lebanon in the hands of Hezbollah. If Israel is not ready for this, so be it—America will continue to pretend to defend human rights. The question of why this human must be a genocidal terrorist might be considered tactless.

Our photo tank is running low, so while I’m gone for the next week you might consider putting together a batch of photos for posting here.  Thanks!

Here is part 2 of Ephraim Heller’s survey of the birds of Bhutan (part 1, with an introduction, is here).  His captions and IDs are indented, and you can enlarge the photos by clicking on them.

Here is installment #2 of photos from my April 2024 birding tour of Bhutan. We begin with a photo of the Paro valley, including the Paro dzong. Paro is the site of Bhutan’s only international airport, as it is the only valley near the capital of Thimpu wide and flat enough for commercial passenger jets. Consequently, most international visitors enter Bhutan here.

Today I post my photos of Phasianidae (pheasants, grouse, and allies) and Columbidae (pigeons and doves). Descriptions of the species below are taken from Wikipedia.

Blood Pheasant (Ithaginis cruentus) male and female. Blood pheasants live in the mountains of Bhutan, Nepal, Sikkim, northern Myanmar, Tibet and central and south-central China, where they prefer coniferous or mixed forests and scrub areas near the snowline. They move their range depending on the season, and are found at higher elevations during the summer. With snow increasing in fall and winter, they move to lower elevations.

Male:

Female:

An Himalayan Monal (Lophophorus impejanus) female. These are native to Himalayan forests and shrublands at elevations of 2,100–4,500 m (6,900–14,800 ft). It is the state bird of Nepal. The male has spectacular colors, but I was able only to photograph the female, which is darn pretty.

A Barred Cuckoo-Dove (Macropygia unchall):

Mountain Imperial-Pigeon (Ducula badia), Bhutan:

An Oriental Turtle-Dove (Streptopelia orientalis):

A Spotted Dove (Spilopelia chinensis). While native to Asia, the species has become established in many areas outside its native range including Hawaii, southern California, Mauritius, Australia, and New Zealand:

A Wedge-tailed Green Pigeon (Treron sphenurus):

Equipment: All animal photos were shot using a Nikon Z9 camera and Nikkor Z 400mm f/2.8 TC VR S lens. Landscape and architectural photos were shot either with a Nikon Z9 and Nikkor Z 70-200mm f/2.8 VR S lens or with an iPhone 11.

You can see more of my photos here.

Heavy, prolonged or painful menstrual periods are associated with more days off school and scoring worse on compulsory exams in a UK study

[UPDATE May 10, 4:00 pm Boston Time, 10:00 pm EU time: AURORAS MAY BE ACTIVE NOW!]

I don’t use exclamation marks in blog post titles lightly. For those of us hoping to see the northern and southern lights (auroras) outside their usual habitat near the Earth’s poles, this is one of those rare weekends where the odds are in our favor. NOAA’s Space Weather Prediction Center has issued a rare G4 forecast (out of a range from G1 to G5) for a major geomagnetic “storm”.

Though the large and active sunspot from earlier this week has moved on, it has been followed by an even larger group of sunspots, so enormous that you can easily see them with eclipse glasses if you’ve kept your pair from last month.

A monster sunspot group on the Sun right now (May 9, 2024).

Powerful solar flares (explosions at the Sun’s visible surface) and the accompanying large coronal mass ejections (“CMEs”, huge clouds of subatomic particles that stream across space from the Sun toward the planets) keep coming, one after another; the second-largest of the week happened just a few hours ago. In the next 24-72 hours, the combined effects of these CMEs may drive the Earth’s magnetic field haywire, leading to northern and southern lights that are much stronger and much more equatorial than usual.

How far south might the northern lights reach? That’s hard to predict, unfortunately. But it wouldn’t be surprising if they reached midway across the United States, and across much of Europe.

If you decide to go looking, keep in mind that dark skies are so important; the auroras can seem quite bright in a dark sky, but they are easily lost to light pollution from city lights or even nearby street lights. Make sure to turn off your car headlights and let your eyes adjust to the dark for a few minutes. The auroras are typically to the north (in the northern hemisphere), but I’ve seen them directly overhead in a strong storm. They’re most often green, but other colors may appear, if you’re lucky. If you’re not sure whether you’re seeing them, take a photo; the camera can pick up dim light and its color more effectively than your eyes can.

As for when to go looking — auroras might happen at any time, from a few hours from now through the weekend, and would potentially be visible whenever the sky is dark. For more detailed information, there are two sources of data that I find useful to monitor:

• First, at this site, you can find near-real-time data on the solar wind— the flow of particles from the Sun — from the ACE satellite, which orbits the Sun almost a million miles from Earth. If you see a sudden wildness in the data, that’s a good sign that a CME has probably passed this satellite, and will arrive at Earth in less than an hour.
• Second, data on the strength of the geomagnetic storm can be found here — but be warned! It is provided only as an average over the past three hours, and only updated every three hours — and so it can be as much as three hours out of date. But if you see the “Kp index” in the red, up around 7 or above, something significant is happening. In a G4 storm, this index can reach 9.

Good luck!!

A centuries-old maths problem asks what shape a circle traces out as it rolls along a line. The answer, dubbed a “cycloid”, turns out to have applications in a variety of scientific fields

Does the repeated stress on your immune system from getting tattoo after tattoo make you better able to fight off infections? No, no it does not.

The post Tattoos Still Won’t Boost Your Immune System first appeared on Science-Based Medicine.

With a bit of training, macaques can make rhythmic movements in time with music, an ability only shown before by a handful of animals