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kottke.org posts about astronomy

Trillions and Trillions and Trillions of Stars

posted by Jason Kottke   May 24, 2021

photo of a cluster of galaxies

This is a photo of a tiny tiny snippet of the universe, taken by the Hubble Space Telescope. Every object you see in the photo is a staggeringly massive galaxy that contains hundreds of billions of stars along with all sort of other things.

Our own galaxy, the Milky Way, is well over one hundred thousand light years across. We only see a pitiful portion of it. Although it contains several hundred billion stars in its expanse, we can only see a fraction of a fraction of them.

And even that doesn’t fully capture the essence of a galaxy, which also has planets, gas, dust, dark matter, and more. Galaxies are colossal objects, their true nature only becoming apparent to us a century ago.

I know I’ve posted photos like this before, but every time I see something like this, my mind boggles anew at the sheer scale and magnitude of it all and I just have to share it.

P.S. And Earth contains the only sentient life in the entire universe? Lol.

The Micrometeorites All Around Us

posted by Jason Kottke   May 20, 2021

microscopic photo of a micrometeorite

microscopic photo of a micrometeorite

microscopic photo of a micrometeorite

microscopic photo of a micrometeorite

Jon Larsen collects and photographs micrometeorites from all over the world, finding them even in urban areas mixed in among terrestrial dust and dirt.

The cosmos is a swirling soup of stardust. Every day, approximately 60 tons of dust from asteroids, comets, and other celestial bodies fall to the Earth. These tiny metallic, alien stones of various shapes, textures, and colors-known as micrometeorites-are some of the oldest pieces of matter in the solar system.

Even though micrometeorites blanket the Earth, scientists have generally only been able to discover them in remote places devoid of human presence, such as Antarctic ice, desolate deserts, and deep-sea sediments. Scientists began searching for micrometeorites in the 1960s, and they predominantly thought the extraterrestrial dust would be impossible to find in urban environments. The conventional wisdom held that densely populated areas had too much man-made sediment that camouflaged the tiny space particles.

But Jon Larsen, a Norwegian jazz musician and creator of Project Stardust, was able to show that it is possible to find micrometeorites in more populated areas. In a study published in January 2017 in the journal Geology, he and his colleagues catalogued more than 500 lustrous micrometeorites (and counting), all recovered from rooftops in urban areas.

Check out Larsen’s Project Stardust for more photos and information on how to hunt for your own. (via the kid should see this)

The Final Border Humanity Will Never Cross

posted by Jason Kottke   May 11, 2021

This video focuses on one of my favorite astrophysics facts: 94% of the observable universe is permanently unreachable by humans. (Unless we discover faster-than-light travel, but that’s fantasy at this point.)

This expansion means that there is a cosmological horizon around us. Everything beyond it, is traveling faster, relative to us, than the speed of light. So everything that passes the horizon, is irretrievably out of reach forever and we will never be able to interact with it again. In a sense it’s like a black hole’s event horizon, but all around us. 94% of the galaxies we can see today have already passed it and are lost to us forever.

“Since you started watching this video, around 22 million stars have moved out of our reach forever.” And future generations, billions of years from now, won’t even be able to see any other galaxies or detect cosmic background radiation, making knowledge about the Big Bang impossible.

Let’s Bask in This Photo of the Sun

posted by Jason Kottke   Apr 27, 2021

The Sun

Astrophotography enthusiast Andrew McCarthy took a 140-megapixel photo of the Sun yesterday and, gosh, the Sun is just so cool to look at. I don’t know if you can see it above, but there’s a little something hidden in the photo, a transiting ISS:

The ISS transiting the Sun

The full-size image is available to McCarthy’s supporters on Patreon.

50 Lovingly Restored Photographs of the Earth Taken by Apollo Astronauts

posted by Jason Kottke   Apr 26, 2021

Earth Restored

Earth Restored

Earth Restored

Earth Restored

For his Earth Restored project, Toby Ord digitally remastered 50 photographs of the whole Earth taken by Apollo astronauts during their missions in the 60s and 70s.

The Apollo photographs are historic works of art. So in restoring them, I sought to bring out their own beauty. I refrained from recomposing the images by cropping, or trying to leave my own mark or interpretation. Perhaps in some cases this would make a more pleasing image, but it was not my aim.

And the Apollo photographs are also a scientific record of what our Earth looks like. In particular, what it would have looked like from the perspective of the astronaut taking the shot. So rather than pumping the saturation or adjusting the colours to what we think the Earth looks like, I wanted to allow us to learn from these photographs something about how it actually appears.

Many of these shots are new to me — the Apollo program and its scientific and cultural output continue to be revelatory 50 years later.

Update: Full resolution images are available when you click through on each photo. You may have to make your browser window wider to see the link. (thx, colin)

A Helicopter Flies on Mars

posted by Jason Kottke   Apr 19, 2021

Ingenuity Shadow

Deployed from NASA’s Perseverance rover, the Ingenuity helicopter took off and hovered for about 30 seconds in its first flight early this morning.

The solar-powered helicopter first became airborne at 3:34 a.m. EDT (12:34 a.m. PDT) — 12:33 Local Mean Solar Time (Mars time) — a time the Ingenuity team determined would have optimal energy and flight conditions. Altimeter data indicate Ingenuity climbed to its prescribed maximum altitude of 10 feet (3 meters) and maintained a stable hover for 30 seconds. It then descended, touching back down on the surface of Mars after logging a total of 39.1 seconds of flight. Additional details on the test are expected in upcoming downlinks.

Ingenuity’s initial flight demonstration was autonomous — piloted by onboard guidance, navigation, and control systems running algorithms developed by the team at JPL. Because data must be sent to and returned from the Red Planet over hundreds of millions of miles using orbiting satellites and NASA’s Deep Space Network, Ingenuity cannot be flown with a joystick, and its flight was not observable from Earth in real time.

NASA livestreamed the team in Mission Control as the test results were transmitted back to Earth. The photo above is of Ingenuity’s shadow taken while in flight by its onboard camera.

Update: Here’s video footage of the first flight:

And there’s always room for a little Great Span on this site. Alex Knapp:

The world’s oldest living person was alive when the Wright Brothers flew at Kitty Hawk and when the first helicopter flew on Mars.

Earthrise

posted by Jason Kottke   Apr 12, 2021

Last month I shared a video of the Earth rising over the surface of the Moon captured by Japan’s Kaguya orbiter. It’s a good clip but quite short and over-narrated. Seán Doran took several Earthrise & Earthset sequences filmed by Kaguya, remastered & upsampled them to 4K resolution, and stitched them together into this wonderful video, set to music by Jesse Gallagher. One of the sequences, which begins around the 5-minute mark, captures a solar eclipse of the Sun by the rising Earth. I hadn’t seen this footage before and had to pick my jaw up off the floor — absolutely spectacular.

A Giant Banana Orbiting the Earth

posted by Jason Kottke   Mar 22, 2021

What if a giant banana was orbiting the Earth at the same distance as the ISS? What would that look like? Well, it would look something like this.

See also If the Planets Were As Close As the Moon.

The Earth Rising Over the Moon

posted by Jason Kottke   Mar 08, 2021

Captured by the Kaguya lunar orbiter on April 5, 2008, this is an HD video of the Earth rising over the surface of the Moon. Watching stuff like this always puts me in a different frame of mind. (Turn off the sound if you don’t want to hear the super-cheesy narration.)

The Secret Message Encoded in the Parachute of the Mars Perseverance Rover

posted by Jason Kottke   Feb 24, 2021

decode instructions for the secret message hidden in the pattern of the Parachute of the Perseverance rover

decode instructions for the secret message hidden in the pattern of the Parachute of the Perseverance rover

NASA engineers encoded a secret message in the parachute the Perseverance rover used to slow its descent to the surface of Mars. Tanya Fish provided a handy guide to decoding it on Twitter and as a PDF available on GitHub.

Onboard Camera Views from Perseverance Rover’s Descent & Touchdown on Mars

posted by Jason Kottke   Feb 23, 2021

Just a few days after the Perseverance rover successfully touched down on Mars, NASA has released onboard video from the descent and landing from multiple perspectives. I watched this with my kids last night and all three of us had our mouths hanging open.

The real footage in this video was captured by several cameras that are part of the rover’s entry, descent, and landing suite. The views include a camera looking down from the spacecraft’s descent stage (a kind of rocket-powered jet pack that helps fly the rover to its landing site), a camera on the rover looking up at the descent stage, a camera on the top of the aeroshell (a capsule protecting the rover) looking up at that parachute, and a camera on the bottom of the rover looking down at the Martian surface.

After watching it again just now, I am struck by two things:

  1. Sometime in my lifetime, live broadcasts from Mars will likely become commonplace. There will be dozens or hundreds of Mars webcams you can pull up on whatever the 2052 internet equivalent is. It will be amazing how boring it all is. (Or perhaps it’ll be boring how amazing it all is.)
  2. That humans landed on the Moon in 1969 was an incredible feat, but a close second is that the first steps were broadcast live from the Moon’s surface to everywhere on the Earth. Unbelievable.

Can’t wait to see more from Perseverance once the science program gets cranking.

Watch NASA’s Perseverance Rover Land on Mars Live

posted by Jason Kottke   Feb 18, 2021

Today is the day! NASA’s latest Mars rover is scheduled to touch down on the surface of Mars at around 3:55pm EST today1 and you can follow along online. You probably know the drill by now: what you’ll be watching isn’t actually live (it’s delayed by 11 minutes & 22 seconds, the time it takes for data to reach the Earth from Mars) and there’s no video to watch…there’s just telemetry from the rover that indicates where it is and what it’s doing. But I can say having watched the Curiosity landing in 2012, it’s still super exciting and nerve-wracking.

NASA has a number of ways to watch online, including their main stream on YouTube (embedded above), en Español, the “clean feed” from mission control without commentary, and a 360-degree stream, as well as options on Twitter, Facebook, Twitch, etc. You can also watch on NASA TV or through NASA apps on your phone, tablet, or TV. The coverage starts at 2:15pm EST (find your local time) and if all goes well, things start to get exciting at about 3:38pm EST and the landing will happen around 3:55pm EST. To get ready, you can check this page for a schedule of what happens when, watch a video about what’s gonna happen, and look at this live simulated view of where the Perseverance spacecraft is now (here too). Good luck, little rover!

  1. All times in this post (and stated by NASA in their schedules) are when we here on Earth will learn of events after the 11 minute & 22 second informational travel time from Mars is factored in. So while the Mars landing will actually occur around 3:44pm EST, we won’t know about it until 3:55pm EST.

The Perseverance Rover Lands on Mars Tomorrow

posted by Jason Kottke   Feb 17, 2021

Curiosity is about to get some company. NASA’s newest rover, Perseverance, is set to land on Mars beginning tomorrow at around 3pm EST. The video above walks us through the 7-minute landing routine in which the rover ditches its spacecraft, heat shields its way through the Martian atmosphere, deploys its parachute, uses an onboard guidance system to navigate to a good landing spot, and finally is lowered down to the surface via a sky crane. The rover’s destination is Jezero Crater, site of an ancient river delta and lakebed.

Jezero Crater tells a story of the on-again, off-again nature of the wet past of Mars. More than 3.5 billion years ago, river channels spilled over the crater wall and created a lake. Scientists see evidence that water carried clay minerals from the surrounding area into the crater lake. Conceivably, microbial life could have lived in Jezero during one or more of these wet times. If so, signs of their remains might be found in lakebed or shoreline sediments. Scientists will study how the region formed and evolved, seek signs of past life, and collect samples of Mars rock and soil that might preserve these signs.

Here’s how you can watch the landing “live” tomorrow (i.e. delayed by the 11 minutes & 22 seconds it takes for signals to travel from Mars). I’ll do a separate post tomorrow w/ the proper YouTube embeds so we can all follow along together.

This New 10 Terapixel Image of the Night Sky Contains 1 Billion Galaxies

posted by Jason Kottke   Feb 08, 2021

portion of a 10 terapixel image of the night sky

After 1405 nights of observation over 6 years, astronomers at three observatories have produced an image of the night sky that contains 10 trillion pixels of data and depicts over a billion galaxies. Bad Astronomy’s Phil Plait has the details.

It’s the result of the DESI Legacy Imagining Surveys, maps of the sky made by the three observatories (the Dark Energy Camera Legacy Survey, the Beijing-Arizona Sky Survey, and the Mayall z-band Legacy Survey, in combination with the orbiting WISE infrared observatory). They mapped the northern sky in seven colors, covering a third of the entire sky — 14,000 square degrees, or the equivalent area of 70,000 full Moons on the sky.

The ultimate goal is to better understand dark energy, the mysterious substance that’s accelerating the expansion of the Universe, by looking at the distribution of galaxies throughout the Universe. They’ll do that by picking tens of millions of the billion galaxies in the data and getting follow-up observations with the Dark Energy Spectroscopic Instrument (DESI), which will take spectra of those galaxies and find their distances.

Since we’ll know their positions on the sky, and their distances, this will make a 3D map of the Universe larger than any ever before.

The photo included at the top of the post is just a tiny tiny bit of the full image — you can pan and zoom the whole thing in this viewer. Be sure to zoom out in increments from the default view so as to fully appreciate just how absurdly large this image (and the universe) is.

Last Night’s Northern Lights

posted by Jason Kottke   Feb 03, 2021

aurora borealis

aurora borealis

aurora borealis

The aurora borealis was amazing last night in Norway. The top photo is from Markus Varik and the bottom two are from Marianne Bergli, who runs a company that offers tours of the aurora. (via @AvatarDomy)

The Northern Lights Photographer of the Year for 2020

posted by Jason Kottke   Dec 10, 2020

The best photos taken of the northern & southern lights in 2020

The best photos taken of the northern & southern lights in 2020

Capture the Atlas has collected some of the best aurora borealis and aurora australis photos taken this year in their 2020 Northern Lights Photographer of the Year competition. I’ve highlighted two photos from the competition above, by Ben Maze & Nico Rinaldi respectively. Maze’s photo, of the aurora australis in Tasmania, is stunning — one of the best astronomy photos I have ever seen. Here’s how he captured it:

Captured in this image is a trifecta of astronomical phenomena that made for some of the best astrophotography conditions one can witness in Australia, namely, the setting Milky Way galactic core, zodiacal light, and of course, the elusive Aurora Australis. On top of this, a sparkling display of oceanic bioluminescence adorned the crashing waves, adding the cherry on top to what was already a breathtaking experience.

Having been out of reception and civilization for over a day, fellow photographer Luke Tscharke and I had no idea the aurora would strike on this night. We’d just heard rumors of a potential solar storm. We could barely contain our excitement when the lights first showed up on our camera’s screens. We later realized we were in the best place on the entire continent to witness the rare show, with Lion Rock being on the southernmost cape of Tasmania and much more cloud-free than the rest of the state at the time.

The colors that our cameras picked up were incredible, too. Rather than the classic green, the display ranged from yellow and orange to pink and purple. When I’d captured enough frames that I was happy with, I simply stood by my camera with my head tilted towards the sky, occasionally swirling my hand around in the sparkling water by my feet. I’m forever grateful for moments in nature like this that show us the true wonders of our planet.

The aurora, the Milky Way, zodiacal light, and bioluminescence all in one image — what a magical conjunction. You can check out the rest of the winners here.

What If the Earth Got Knocked Out of the Solar System?

posted by Jason Kottke   Dec 03, 2020

The Milky Way galaxy may be home to billions or even trillions of rogue planets (planets that don’t orbit stars). In this video, Kurzgesagt considers how the Earth could go rogue (by following a nearby massive star away from the Sun) and what would happen to our oceans, atmosphere, and lives if it happened.

The first part of the video is pretty bleak — “as the days turn dark, the final winter of humanity would begin” — while the second part is hopeful: we’ll be able to predict our ejection thousands of years before it happens and may be able to prepare. In light of the world’s response to the pandemic and climate change, it would certainly be interesting to see if human civilization could get it together to save itself from a cold death in outer space. I have no doubt that scientist could accurately diagnose the problem and supply solutions, but the politics would be a total mess.

Here’s What 10 Million Stars Look Like

posted by Jason Kottke   Oct 28, 2020

10 Million Stars

Using the Dark Energy Camera at the Cerro Tololo observatory in Chile, astronomers took an image of the stars clustered around the center of our Milky Way galaxy that shows about 10 million stars. Check out the zoomable version for the full experience.

Looking at an image like this is always a bit of a brain-bender because a) 10 million is a huge number and b) the stars are so tightly packed into that image and yet c) that image shows just one tiny bit of our galactic center, d) our entire galaxy contains so many more stars than this (100-400 billion), and e) the Universe perhaps contains as many as 2 trillion galaxies. And if I’m remembering my college math correctly, 400 billion × 2 trillion = a metric crapload of stars. (via bad astronomy)

A 2.5 Gigapixel Image of the Orion Constellation

posted by Jason Kottke   Oct 26, 2020

Orion Constellation Gigapixel

Amateur astronomer Matt Harbison has been working for the past five years on capturing a detailed image of the Orion constellation. He recently completed the project and the result is this 2.5 gigapixel photo mosaic composed of 12,816 individual photos. From PetaPixel, which has a good writeup of the project, a taste of the challenges involved with constructing this image:

Even after all the images were shot and each panel completed, the finished image did not come together smoothly. “I began in 2015 on a Mac Pro with 2 Xeon Processors and 64GB of RAM. This machine was easily one of the fastest computers of the day, and it carried me all the way up to panel 47 where I believe I hit the RAM limit of the computer.”

It would take five years from that point for technology to catch up to Harbison’s needs as he wouldn’t have a computer powerful enough to complete the task until August of 2020. “The new computer is an AMD Threadripper with 24 cores and 256GB of memory,” Harbison said. “It took a total of 23 hours to provide an astrometric solution for all 200 panels and then an additional 19 hours to merge into the gradient merge mosaic tool.”

What an amazing thing to be able to make from your backyard.

Winners of the 2020 Astronomy Photographer of the Year Contest

posted by Jason Kottke   Sep 22, 2020

2020 Astronomy Photographer of the Year

2020 Astronomy Photographer of the Year

2020 Astronomy Photographer of the Year

2020 Astronomy Photographer of the Year

2020 Astronomy Photographer of the Year

The winning entries from the Insight Investment Astronomy Photographer of the Year 2020 competition are here and they are spectacular. As longtime readers can attest, I will never get tired of looking at photos of the sky and space.

Above from top to bottom: Nicolas Lefaudeux’s tilt-shift shot of the Andromeda Galaxy, Alain Paillou’s ultra-contrasty photo of the Moon, Kristina Makeeva’s aurora shot, Evan McKay’s self-portrait under the Milky Way, and Olga Suchanova’s 3-month exposure of the Sun’s path through the sky using a beer can pinhole camera. You can read a little bit about how Suchanova got that shot on 35mmc:

If exposure times on the order of minutes seem long, try months. Olga Suchanova (London, UK) used a pinhole camera made from a beercan — and not just any beercan, but a Peter Saville design for the Tate Modern — to record the solargraph below.

She used Ilford paper, exposed for 3 or 4 months at an art residency in Almeria, Spain. The long exposure traces the sun’s path across the sky over multiple days — sunny days make brighter lines, and as spring turns to summer, the sun rises higher in the sky. The fantastic colours — another consequence of the long exposure — are created spontaneously on black and white paper, without the need for development or any other chemical processing.

Scientists Detect Signs of Possible Life on Venus

posted by Jason Kottke   Sep 14, 2020

The planet Venus

A group of astronomers have announced that they’ve discovered evidence that there may be life in the atmosphere of Venus.

The astronomers, who reported the finding on Monday in a pair of papers, have not collected specimens of Venusian microbes, nor have they snapped any pictures of them. But with powerful telescopes, they have detected a chemical — phosphine — in the thick Venus atmosphere. After much analysis, the scientists assert that something now alive is the only explanation for the chemical’s source.

Some researchers question this hypothesis, and they suggest instead that the gas could result from unexplained atmospheric or geologic processes on a planet that remains mysterious. But the finding will also encourage some planetary scientists to ask whether humanity has overlooked a planet that may have once been more Earthlike than any other world in our solar system.

“This is an astonishing and ‘out of the blue’ finding,” said Sara Seager, a planetary scientist at the Massachusetts Institute of Technology and an author of the papers (one published in Nature Astronomy and another submitted to the journal Astrobiology). “It will definitely fuel more research into the possibilities for life in Venus’s atmosphere.”

New Solar Telescope Finds “Campfires” on the Sun

posted by Jason Kottke   Jul 24, 2020

Sun Campfires

The European Space Agency’s Solar Orbiter is not even at its closest distance to the Sun and its telescope has already captured some images that reveal new information about our star, including features called “campfires” that are too small to have been captured by previous instruments. From the description of the video embedded above:

This animation shows a series of close-up views captured by the Extreme Ultraviolet Imager (EUI) at wavelengths of 17 nanometers, showing the upper atmosphere of the Sun, or corona, with a temperature of around 1 million degrees.

These images reveal a multitude of small flaring loops, erupting bright spots and dark, moving fibrils. A ubiquitous feature of the solar surface, uncovered for the first time by these images, have been called ‘campfires’. They are omnipresent miniature eruptions that could be contributing to the high temperatures of the solar corona and the origin of the solar wind.

The Solar Orbiter can also peek around the back side of the Sun for the first time:

“Right now, we are in the part of the 11-year solar cycle when the Sun is very quiet,” says Sami Solanki, the director of the Max Planck Institute for Solar System Research in Gottingen, Germany, and PHI Principal Investigator. “But because Solar Orbiter is at a different angle to the Sun than Earth, we could actually see one active region that wasn’t observable from Earth. That is a first. We have never been able to measure the magnetic field at the back of the Sun.”

As revealing as these first images are, at its closest approach later in the mission the Solar Orbiter’s resolving power will roughly double. Can’t wait to see what else it turns up.

Gorgeous 4K Video of Mars

posted by Jason Kottke   Jul 21, 2020

To create this ultra HD footage of the surface of Mars, high-definition panoramas created from hundreds of still photos taken by the Mars rovers are panned over using the Ken Burns effect. The end product is pretty compelling — it’s not video, but it’s not not video either.

A question often asked is: ‘Why don’t we actually have live video from Mars?’

Although the cameras are high quality, the rate at which the rovers can send data back to earth is the biggest challenge. Curiosity can only send data directly back to earth at 32 kilo-bits per second.

Instead, when the rover can connect to the Mars Reconnaissance Orbiter, we get more favourable speeds of 2 Megabytes per second.

However, this link is only available for about 8 minutes each Sol, or Martian day.

As you would expect, sending HD video at these speeds would take a long long time. As nothing really moves on Mars, it makes more sense to take and send back images.

(thx, paul)

The Best Photos of Comet Neowise

posted by Jason Kottke   Jul 16, 2020

Sometimes I forget what a big space dork I am and then a comet comes along and I’m texting everyone I know to get their asses outside to see the amazing sky thing. Anyway, what I’m trying to say is that this is a Comet Neowise fan blog now. After seeing it last night in my backyard,1 I went looking for some of the best photos of it.

My favorite so far is from Thierry Legault (website) of the comet over Mont-Saint-Michel in France.

Comet Neowise

In Focus’s Alan Taylor shared a selection of photographs from around the world, including this one from Mika Laureque.

Comet Neowise

Colossal featured this shot by Lester Tsai of Neowise directly over Mt. Hood. Dang.

Comet Neowise

More Comet Neowise photography can be see at USA Today, NASA, Sky & Telescope, and Astronomy Picture of the Day (1, 2, 3, 4, 5).

  1. After seeing it briefly two nights ago before some haze settled in (and only then with the aid of binoculars), I stepped out on my deck last night just after 10pm and bam, it was right there, totally visible with the naked eye. I grabbed the binoculars and got a pretty good view and then got out the telescope. Whoa, papa. Totally mind-blowing.

How to Find Comet NEOWISE in the Night Sky This Month

posted by Jason Kottke   Jul 13, 2020

If you live in the US and Canada, you might have the opportunity to check out Comet NEOWISE over the next few weeks with a good pair of binoculars or even with the naked eye. EarthSky has the skinny.

By mid-July (around July 12-15), the comet will also become visible at dusk (just after sunset), low in the northwest horizon, for observers in the mid- and northern U.S. How can it be visible in both dawn and dusk? The answer is that the comet is now very far to the north on the sky’s dome. For those at latitudes like those in the southern U.S. (say, around 30 degrees north latitude), the comet is very nearly but not quite circumpolar, that is, it’s nearly in the sky continually, but it isn’t quite … that’s why we at southerly latitudes will have a harder time spotting it in the evening.

Comet NEOWISE

It appears this comet is holding up better than Comet ATLAS did earlier in the year. Here’s a beautiful time lapse of NEOWISE rising over the Adriatic Sea in the early dawn:

And a time lapse of the comet from the International Space Station (it starts rising around the 3-minute mark):

A Decade of Sun

posted by Jason Kottke   Jun 29, 2020

For the past 10 years now, NASA’s Solar Dynamics Observatory (SDO) has been capturing an image of the Sun every 0.75 seconds. To celebrate, NASA created this 61-minute time lapse video of all ten years, with each second representing one day in the Sun’s life. They have helpfully highlighted some noteworthy events in the video, including solar flares and planetary transits.

12:24, June 5, 2012 — The transit of Venus across the face of the Sun. Won’t happen again until 2117.

13:50, Aug. 31, 2012 — The most iconic eruption of this solar cycle bursts from the lower left of the Sun.

43:20, July 5, 2017 — A large sunspot group spends two weeks crossing the face of the Sun.

See also Gorgeous Time Lapse of the Sun.

Colorful New Geological Map of the Moon

posted by Jason Kottke   Apr 30, 2020

Moon Geological Map

Moon Geological Map

In collaboration with NASA and the Lunar and Planetary Institute, the USGS has released the first complete geological map of the Moon’s surface.

This new work represents a seamless, globally consistent, 1:5,000,000-scale geologic map derived from the six digitally renovated geologic maps (see Source Online Linkage below). The goal of this project was to create a digital resource for science research and analysis, future geologic mapping efforts, be it local-, regional-, or global-scale products, and as a resource for the educators and the public interested in lunar geology.

Strange Maps has more information on how the map came to be and what it shows.

The map was created by the U.S. Geological Service’s Astrogeology Science Center in Flagstaff, Arizona. In collaboration with NASA and the Lunar and Planetary Institute, it combined six ‘regional’ maps of the Moon made during the Apollo era (1961-1975) with input from more recent unmanned lunar missions.

This included data on the polar regions from NASA’s Lunar Orbiter Laser Altimeter (LOLA) and close-ups of the equatorial zone from the Japanese Space Agency’s recent SELENE mission.

The two images above show the entire map and a detailed view of a single area (which includes the landing sites of 3 Apollo missions) while the video shows a rotating globe version of the map.

Hubble Telescope Watches the Rare Disintegration of a Comet

posted by Jason Kottke   Apr 29, 2020

Last month, I told you about Comet ATLAS, which at that time looked capable of putting on a real show in the night sky.

Except, since its discovery, the comet has been brightening at an almost unprecedented speed. As of March 17, ATLAS was already magnitude +8.5, over 600 times brighter than forecast. As a result, great expectations are buzzing for this icy lump of cosmic detritus, with hopes it could become a stupendously bright object by the end of May.

It turns out the increase in brightness was fleeting — and possibly due to the comet breaking apart. In the past week, the Hubble Space Telescope has gotten two good looks at the disintegrating comet, identifying that the main mass has broken into about 30 fragments.

Comet Atlas Hubble

Comet Atlas Hubble

“This is really exciting — both because such events are super cool to watch and because they do not happen very often. Most comets that fragment are too dim to see. Events at such scale only happen once or twice a decade,” said the leader of a second Hubble observing team, Quanzhi Ye, of the University of Maryland, College Park.

The results are evidence that comet fragmentation is actually fairly common, say researchers. It might even be the dominant mechanism by which the solid, icy nuclei of comets die. Because this happens quickly and unpredictably, astronomers remain largely uncertain about the cause of fragmentation. Hubble’s crisp images may yield new clues to the breakup. Hubble distinguishes pieces as small as the size of a house. Before the breakup, the entire nucleus may have been no more than the length of two football fields.

Recently Discovered Comet Might Put On a Show

posted by Jason Kottke   Mar 23, 2020

Back in late December, a new comet called Comet ATLAS (or C/2019 Y4) was discovered by a robotic astronomical survey on the lookout for objects that may strike the Earth. Don’t worry, Comet ATLAS isn’t going to hit us, but it has a chance to put on quite a show.1 It didn’t seem like much at first, but since its discovery Comet ATLAS has gotten brighter much faster than scientists have expected.

When astronomers first spotted Comet ATLAS in December, it was in Ursa Major and was an exceedingly faint object, close to 20th magnitude. That’s about 398,000 times dimmer than stars that are on the threshold of naked-eye visibility. At the time, it was 273 million miles (439 million kilometers) from the sun.

But comets typically brighten as they approach the sun, and at its closest, on May 31, Comet ATLAS will be just 23.5 million miles (37.8 million km) from the sun. Such a prodigious change in solar distance would typically cause a comet to increase in luminosity by almost 11 magnitudes, enough to make ATLAS easily visible in a small telescope or a pair of good binoculars, although quite frankly nothing really to write home about.

Except, since its discovery, the comet has been brightening at an almost unprecedented speed. As of March 17, ATLAS was already magnitude +8.5, over 600 times brighter than forecast. As a result, great expectations are buzzing for this icy lump of cosmic detritus, with hopes it could become a stupendously bright object by the end of May.

But the brightening could also be a sign that the comet is ejecting a lot of material because it’s burning itself out, so grain of salt. But if keeps brightening at a good pace, it could be visible during the day in the northern hemisphere.

If Atlas manages to remain intact, some in the field have suggested it could grow from magnitude +1 to possibly -5. At the brightest extreme, it could be visible even during the day.

The location of the comet is also notable-unlike more recent comets, it will be best viewed in the Northern Hemisphere.

Chuck Ayoub recently captured the comet arcing across the night sky with his backyard astrophotography rig:

Oh I hope Comet ATLAS can keep it together. I vividly remember going outside in rural Wisconsin darkness to see the tail of Comet Hyakutake stretch halfway across the sky. One of the most amazing things I’ve ever seen.

Update: It looks as though Comet ATLAS will not be dazzling naked-eye observers later this spring — the comet seems to have broken into 3 or 4 pieces as it nears the Sun.

Comet Atlas Broken

  1. Although I guess Comet ATLAS is good news if you’re looking for signs of the apocalypse too. Pandemic: check. Bright new light in the sky: check.

Mysterious Sources of Light Pollution

posted by Jason Kottke   Mar 06, 2020

If you look at online light pollution maps, most light pollution comes from cities, but Alex Altair noticed that there are some unexpected sources of light out there as well. For instance, this sprawling site in North Dakota is one of the brightest places in the country despite what Altair calls “an intense lack of urbanization”.

Light pollution in North Dakota

The light in that area is from oil drilling & extraction in the area.

The light pollution comes from the associated gas flares. These flares are deliberate, continuously burning fires, and they convert methane, a potent greenhouse gas, into CO2, a much less potent greenhouse gas.

Intense heat also accounts for an odd light source in Hawaii — you can probably guess, but you’ll have to click through to confirm.

See also Lost in Light: How Light Pollution Obscures Our View of the Night Sky.