Meet NGC 2841

Pink Robin Bird

The pink robin is a small passerine bird native to southeastern Australia.

Its natural habitats are cool temperate forests of far southeastern Australia.

Like many brightly coloured robins it is sexually dimorphic.

Measuring 5.3 in in length, the robin has a small, thin, black bill, and dark brown eyes and legs.

The male has a distinctive white forehead spot and pink breast, with grey-black upperparts, wings and tail. The belly is white.

Its range is the forests of southern Victoria and neighbouring parts of South Australia and New South Wales, and Tasmania.

Pink Robin Bird

I knew that the eruption/explosion of Krakatoa was the loudest sound in recorded history, but I couldn’t quite grasp how loud until I got a couple details of perspective. This was in 1883.

The shock wave ruptured the eardrums of sailors 40 miles away.

The explosion was heard more than 3,000 miles away, and recorded all over the world.

It made tsunamis nearly 100 feet high.

Now picture this happening in modern times, with modern communications. Not only would there be uncountable videos and whatnot, but the timing is what really gets me. Imagine you’re going about your day, scrolling social media, and posts start pouring in about an apocalyptic volcano on the other side of the continent. The news are full of it. You spend ages glued to the screen; this isn’t remotely close to you, but it’s a big deal, and you know people who live closer to it.

Three hours later, something explodes outside. Propane tank? Car fire? Some jackass with illegal firecrackers?

Nope. That was the sound wave, finally reaching you.

Symmetry Magazine

How JWST will test models of cold dark matter

By Madeleine O’Keefe

Two projects in JWST’s first observation cycle will probe the nature of dark matter.

On Christmas morning of 2021, an Ariane 5 CEA rocket blasted off from Kourou, French Guinea. It carried with it the largest and most sophisticated space telescope ever built: the James Webb Space Telescope.

Since then, JWST has reached its orbit about 1 million miles from Earth, unfurled its tennis-court-sized sunshield, and aligned its 18 hexagonal mirror segments. The telescope’s first images are expected by summer.

Over the next decade, JWST will make cutting-edge observations to help scientists answer myriad outstanding questions in astronomy—including questions about the nature of dark matter.

Hot, warm or cold Dark matter is an enigmatic substance that scientists believe accounts for 85% of matter in the universe. But so far it has not been observed directly; scientists can infer dark matter’s presence only by observing its gravitational effects on normal matter.

Different theories posit different types of dark-matter particles. Dark-matter candidates considered “hot” or “warm” are particles that would have moved so quickly in the early universe that gravity would not have been able to confine them. On the other hand, dark-matter candidates considered “cold” are thought to have moved so slowly that gravity would have formed them into small dark-matter structures that eventually would have coalesced into larger, “clumpy” ones.

“Decades’ worth of computer simulations have tested how structure forms and grows under the hypothesis of cold dark matter,” says Matthew Walker, an associate professor of physics at Carnegie Mellon University.

Cold dark-matter simulations show dark matter clumping into small blobs, which encounter other blobs and merge together, continually snowballing until large structures like the Milky Way are formed. These gravitationally bound blobs of dark matter are known as halos.

JWST can see your halo Anna Nierenberg, assistant professor of physics at University of California, Merced, was awarded 39 hours of observing time during JWST’s Cycle 1 to look for small dark-matter halos.

Many models, including the baseline dark-matter model, predict the existence of small (107 solar mass) halos that do not actually contain galaxies. Such a halo would “just be a blob of dark matter” with no stars inside it, Nierenberg says.

If there are no stars within these blobs of invisible material, how can we even try to detect them? Nierenberg and her team of nearly 20 scientists in the US, Canada, the United Kingdom, Switzerland, Spain, Belgium and Chile are using a phenomenon called gravitational lensing.

Born of Albert Einstein’s theory of general relativity, gravitational lensing says that matter bends spacetime and, subsequently, any light that encounters it. If light from a distant source travels through the universe toward Earth and passes by a massive object—such as a blob of dark matter—the light will be warped around it. If the in-between object is massive enough, the light is deflected in such a way that we’ll see up to four images of the light source appearing around the mass.

Nierenberg’s group will measure the number of small dark-matter halos by observing a sample of quasars (supermassive black holes at cosmological distances surrounded by dusty accretion disks) that have been gravitationally lensed. Detecting small halos would be a triumph for the cold dark-matter theory; conversely, not detecting small halos would imply that cold dark matter does not exist.

Because the light from these quasars must travel a great distance in an ever-expanding universe, it is stretched along the way, pulling its wavelengths into the infrared range. The mid-infrared wavelengths they are observing are almost impossible to see with ground-based telescopes. “We’re going to be observing with absolute reddest bands that JWST can accommodate,” Nierenberg says.

These wavelengths cannot be observed by the Hubble Space Telescope, which studies gravitational lensing at visible wavelengths. And older space-based telescopes that can see in the mid-infrared don’t have the resolution to separate the different lenses. Making these observations in mid-IR requires the high spatial resolution that only the JWST can provide, Nierenberg says.

Daniel Gilman, a postdoc at the University of Toronto and one of Nierenberg’s co-investigators, says, “The kind of data that we can get with JWST is unique and much more powerful or constraining than the kind of data that we could get with Hubble or from the ground.”

Nierenberg says, “I really believe that this is going to be a huge scientific step forward.”

Looking far and wide Walker is leading another dark-matter project in JWST’s Cycle 1, but his group didn’t apply for observing time. Instead, they are using data that JWST is collecting for other programs.

Walker’s group’s “archival research” is looking inside dwarf galaxies to find wide binary stars, systems of two stars orbiting each other at relatively large distances (on the order of one parsec, slightly less than the distance between the sun and our closest neighbor, Proxima Centauri).

“Because [wide binary stars] are so far apart, they’re very fragile systems,” says Walker. “If, say, a little dark-matter halo were to fly past a wide binary-star system, it could exchange energy with either or both of the stars in that system. And it just takes a small fraction of a fraction of a percent increase in the energy of either star to rip the pair apart.”

If Walker’s team finds wide binary stars, “we can be reasonably confident that those sub-galactic cold dark matter halos don’t exist,” he says. “And that, then, would be a real problem for the cold dark-matter model in general.”

That’s what Katharine Lee, a junior physics major at Carnegie Mellon in Walker’s group, likes about the project. “I particularly think this research is really interesting because the current framework for what we think of as the structure of dark matter is the cold dark-matter model, and the research that Professor Walker’s doing could potentially invalidate that.”

If the group did not find wide binary stars, it could be a sign that they were destroyed by dark matter. But it would not prove that they were destroyed—they may just have never formed in these dwarf galaxies in the first place.

Walker says that JWST is an ideal tool for this search because of its “exquisite sensitivity to faint objects,” as well as the telescope’s abilities to take high-quality images and distinguish pairs of sources at very small separations. And thanks to its 21-foot-diameter primary mirror, JWST will see farther than any other telescope ever built.

“I think JWST is going to give us a new and really powerful angle,” says Jorge Peñarrubia, a professor at the University of Edinburgh and one of Walker’s co-investigators. “But even if that fails, we’ll find other ways.”

Indeed, there are many other techniques that scientists use to search for dark matter, including direct searches by physics experiments. And both Nierenberg and Walker are using gravitational lensing and wide binary-star methods on data from the Hubble Space Telescope while they wait for JWST to open its eyes.

Future JWST science programs might further explore the mysteries of dark matter, whether through gravitational lensing or perhaps by observing statistics of galaxy evolution that scientists can then compare to dark-matter theories.

“We don’t lack theories of what dark matter could be. There are a lot of them,” Gilman says. “What we lack are observations that wield a lot of constraining power over these theories. And that’s something that JWST is going to give us.”

Illustration by Sandbox Studio, Chicago with Olena Shmahalo

The Sun is White, not Yellow.

Tracking the Sun’s Cycles

Scientists just announced that our Sun is in a new cycle.

Solar activity has been relatively low over the past few years, and now that scientists have confirmed solar minimum was in December 2019, a new solar cycle is underway — meaning that we expect to see solar activity start to ramp up over the next several years.

The Sun goes through natural cycles, in which the star swings from relatively calm to stormy. At its most active — called solar maximum — the Sun is freckled with sunspots, and its magnetic poles reverse. At solar maximum, the Sun’s magnetic field, which drives solar activity, is taut and tangled. During solar minimum, sunspots are few and far between, and the Sun’s magnetic field is ordered and relaxed.

Understanding the Sun’s behavior is an important part of life in our solar system. The Sun’s violent outbursts can disturb the satellites and communications signals traveling around Earth, or one day, Artemis astronauts exploring distant worlds. Scientists study the solar cycle so we can better predict solar activity.

Measuring the solar cycle

Surveying sunspots is the most basic of ways we study how solar activity rises and falls over time, and it’s the basis of many efforts to track the solar cycle. Around the world, observers conduct daily sunspot censuses. They draw the Sun at the same time each day, using the same tools for consistency. Together, their observations make up the international sunspot number, a complex task run by the World Data Center for the Sunspot Index and Long-term Solar Observations, at the Royal Observatory of Belgium in Brussels, which tracks sunspots and pinpoints the highs and lows of the solar cycle. Some 80 stations around the world contribute their data.

Credit: USET data/image, Royal Observatory of Belgium, Brussels

Other indicators besides sunspots can signal when the Sun is reaching its low. In previous cycles, scientists have noticed the strength of the Sun’s magnetic field near the poles at solar minimum hints at the intensity of the next maximum. When the poles are weak, the next peak is weak, and vice versa.

Another signal comes from outside the solar system. Cosmic rays are high-energy particle fragments, the rubble from exploded stars in distant galaxies that shoot into our solar system with astounding energy. During solar maximum, the Sun’s strong magnetic field envelops our solar system in a magnetic cocoon that is difficult for cosmic rays to infiltrate. In off-peak years, the number of cosmic rays in the solar system climbs as more and more make it past the quiet Sun. By tracking cosmic rays both in space and on the ground, scientists have yet another measure of the Sun’s cycle.

Since 1989, an international panel of experts—sponsored by NASA and NOAA—meets each decade to make their prediction for the next solar cycle. The prediction includes the sunspot number, a measure of how strong a cycle will be, and the cycle’s expected start and peak. This new solar cycle is forecast to be about the same strength as the solar cycle that just ended — both fairly weak. The new solar cycle is expected to peak in July 2025.

Learn more about the Sun’s cycle and how it affects our solar system at nasa.gov/sunearth.

Make sure to follow us on Tumblr for your regular dose of space: http://nasa.tumblr.com.

I'm currently working on an animatic, could you give me any advice?

1.

2.

3.

4.

5.

I still haven’t taken any animation or storyboarding classes, but these are general TECHNICAL tips I’ve learned online and through trying to fix my own boards. Definitely practice with things your passionate about/interested as it’ll make the process so much more fun (: for me the technical parts aren't the hardest, moreso actually visualizing and deciding the scenes mentally, which takes practice.

Also 6 cuz yeee:

I had a classmate laugh cuz I said I used wmm for my boards and he thought he needed a fancy $7 blue pencil LIKE NO BRO JUST USE WHAT YOU HAVE IF YOU CAN’T AFFORD THINGS LOLLLL. I have a small huion screen now, but it’s down to preference cuz honestly I prefer paper over digital 0′;

Good luck though! Once I take classes or if I have more tips id gladly share them with yall (:

Random Fact #3,062

The wind on Neptune can blow at speeds of 2,000 km/hour.

The winds causing the Great Dark Spot specifically have been measured to be around 1,127 km/hour.

how to hit your guys with the crust rays

a friend of mine was having trouble with a character of hers, he was middle-aged but looked too young, so she came to me for help. i'm something of a middle-aged-man-fan so i whipped up this quick thing to help her out. it might be useful to somebody out there so i'll share it here too!

Deltoid animated study, this muscle helps raising the arm!