kottke.org posts about astronomy
In looking over the shortlist for the Astronomy Photographer of the Year 2025 competition, I thought about how I’ve seen thousands or even tens of thousands of incredible astronomical images and yet there are always new, mind-blowing things to see. Like this 500,000-km Solar Prominence Eruption by PengFei Chou:
Or Close-up of a Comet by Gerald Rhemann and Michael Jäger:
Or Electric Threads of the Lightning Spaghetti Nebula by Shaoyu Zhang (Lightning Spaghetti Nebula!!!):
Or Dragon Tree Trails by Benjamin Barakat:
Teasingly, the official site only has a selection of the shortlisted entries but if you poke through the posts at Colossal, PetaPixel, and DIY Photography, you can find some more of them. (via colossal)
The Vera C. Rubin Observatory in Chile is operational and will soon embark on its primary mission: to take a detailed image of the sky every night for the next ten years.
A powerful new observatory has unveiled its first images to the public, showing off what it can do as it gets ready to start its main mission: making a vivid time-lapse video of the night sky that will let astronomers study all the cosmic events that occur over ten years.
“As the saying goes, a picture is worth a thousand words. But a snapshot doesn’t tell the whole story. And what astronomy has given us mostly so far are just snapshots,” says Yusra AlSayyad, a Princeton University researcher who oversees image processing for the Vera C. Rubin Observatory.
“The sky and the world aren’t static,” she points out. “There’s asteroids zipping by, supernovae exploding.”
And the Vera C. Rubin Observatory, conceived nearly 30 years ago, is designed to capture all of it.
These images will revolutionize how astronomy is done:
Astronomy is following in the path of scientific fields like biology, which today is awash in DNA sequences, and particle physics, in which scientists must sift through torrents of debris from particle collisions to tease out hints of something new.
“We produce lots of data for everyone,” said William O’Mullane, the associate director for data management at the observatory. “So this idea of coming to the telescope and making your observation doesn’t exist, right? Your observation was made already. You just have to find it.”
“Your observation was made already. You just have to find it.” I love that.
The Rubin team has released some images from the telescope’s initial run, to inform the public of what the project is capable of. In less than a half-day’s operation, the Rubin discovered 2,104 new asteroids in our solar system.
In about 10 hours of observations, NSF-DOE Vera C. Rubin Observatory discovered 2104 never-before-seen asteroids in our Solar System, including seven near-Earth asteroids (which pose no danger). Annually, about 20,000 asteroids are discovered in total by all other ground and space-based observatories. Rubin Observatory alone will discover millions of new asteroids within the first two years of the Legacy Survey of Space and Time. Rubin will also be the most effective observatory at spotting interstellar objects passing through the Solar System.
Not bad, rook. The team has set up a dedicated image viewer for their massive images.
You can read more about the Rubin at The Atlantic, The Rubin Observatory Is a Cosmic Cathedral, written by Michael Jones McKean, the observatory’s artist in residence:
Rubin is also a rare scientific megaproject that feels excitingly relatable. Instruments such as particle accelerators, neutrino detectors, and even radio telescopes might command our awe, but they roam in realms far outside sensorial experience. At its core, Rubin is an optical telescope. This links it to a long continuum of prosthetic tools that help our bodies better do what they already do naturally — see and process light.
And a trio of videos on how the observatory works from BBC News, New Scientist, and astrophysicist Becky Smethurst.
The NY Times has a nice feature on NASA astronaut Don Pettit’s photography from his latest stay in space, a 220-day mission aboard the ISS.
Now, you know I like a good astronomical image (like the one above of an ISS sunrise), but the thing that really caught my eye was the video of Pettit’s experiment involving charged water droplets and a teflon needle:
I could watch that allllll day long.
More Pettit: Swirling Green Aurora Captured From the ISS.
I don’t have a whole lot to say about this video except wow. Wow wow. It’s almost inconceivable that we live in a world of sights like this. Feels like science fiction but is actually real. Captured by NASA astronaut Don Pettit aboard the ISS.
TIL I learned about gravastars (aka a gravitational vacuum star), theoretical objects related to black holes. Both are massive & dense, but instead of a singularity surrounded by an event horizon, gravastars are made up of dark energy surrounded by a extremely thin shell of exotic matter.
The shell of the gravastar is utterly dark and the coldest thing in the universe, only a billionth of a degree above absolute zero. If we look at it in deep infrared, even the cosmic microwave background glows bright in comparison. It is made from an entirely new, unique and extreme matter that is at the very limit of what is physically possible in nature and doesn’t have a name yet. Actually, the shell is so incredibly thin that atoms seem truly gigantic next to it.
The Hubble Space Telescope was launched into space 35 years ago and in celebration of that milestone, Alan Taylor collected some recent images from the Hubble, whose mission is still ongoing.
Photographer Joshua Rozells on his photo of our increasingly crowded night skies:
The light pollution caused by satellites is quickly becoming a growing problem for astronomers. In 2021, over 1700 spacecrafts and satellites were put into orbit. Light pollution caused by SpaceX’s Starlink satellites are the worst offenders because they are low Earth orbit satellites, and they travel in satellite trains. One can only assume the issue will exponentially increase in the next few years, with SpaceX alone intending to launch over 40,000 satellites in total. The space industry is almost entirely unregulated, with no limits on the amount of satellites that anyone is able to launch and there is currently no regulation in place to minimise the light pollution they cause.
The Hubble Space Telescope “has observed some fascinating cosmic wonder every day of the year, including on your birthday”. Just enter your month and day of birth to find out what it saw. My birthday image is of the Egg Nebula (shown above):
Where is the center of the Egg Nebula? Like a baby chick pecking its way out of an egg, the star in the center of the Egg Nebula is casting away shells of gas and dust as it slowly transforms itself into a white dwarf star.
The Egg Nebula is a rapidly evolving pre-planetary nebula spanning about one light year toward the constellation of Cygnus. Thick dust blocks the center star from view, while the dust shells further out reflect light from this star. Light vibrating in the plane defined by each dust grain, the central star and the observer is preferentially reflected, causing an effect known as polarization. Measuring the orientation of the polarized light for the Egg Nebula gives clues as to location of the hidden source. The above image taken by the Advanced Camera for Surveys on the Hubble Space Telescope is false-color coded to highlight the orientation of polarization.
Cool! I like my birthday nebula. (via the morning news)
From astronomer Yuri Beletsky, a photo of Comet C/2024 G3 (ATLAS) arching over ESO’s Paranal Observatory in Chile.
Unfortunately, it seems like the comet disintegrated as it swooped around the Sun, always a danger.
The nucleus of Comet ATLAS (C/2024 G3) held together during a brutal perihelion but not for long. Lionel Majzik of Hungary was the first to report and record dramatic changes in the comet between January 18th and 19th. The bright, strongly condensed head rapidly became more diffuse, a sure sign that its nucleus was disintegrating based on past observations of crumbling comets. His superb sequence, photographed remotely from Chile, clearly reveal the dramatic transformation, which was later confirmed by Australian observers.
The tail will be visible for a few days after the breakup — such comets are called “headless wonders” by astronomers. (via @philplait.bsky.social)
NASA’s Goddard Space Flight Center has released a pair of visualizations of the phases the Moon will go through in 2025, one for the northern hemisphere above and one for the southern hemisphere below:
Look at that sucker wobble! Each frame of the 4K video represents one hour and there are lots of locations labeled on the map, including the landing sites of the Apollo missions.
But also: How have I never noticed that the Moon is upside-down in the southern hemisphere?! I mean, it makes total sense but I’ve just never noticed or thought it through. 🤯 (via the kid should see this)
I know astronomical imagery is on the verge of being over-processed these days (those colors don’t exist out there!), but this image from the JWST is shocking. Clear evidence of Sesame Street’s Yip Yip Martians from billions of years ago. What did Jim Henson know and when did he know it?
Wow, check out this just-released image from the JWST team of star cluster NGC 602.
The local environment of this cluster is a close analogue of what existed in the early Universe, with very low abundances of elements heavier than hydrogen and helium. The existence of dark clouds of dense dust and the fact that the cluster is rich in ionised gas also suggest the presence of ongoing star formation processes. This cluster provides a valuable opportunity to examine star formation scenarios under dramatically different conditions from those in the solar neighbourhood.
It is very worth your time to click through and look at this image in all of its massive celestial glory. I found this image via Phil Plait, who calls it “one of the most jaw-droppingly mind stomping images I’ve seen from JWST” and, directing us back to the science (remember the science?!), notes that NGC 602 is actively forming stars (it’s only about 5 million years old) and that it depicts “the first young brown dwarfs outside our Milky Way”. Cool!
Out today from National Geographic is Infinite Cosmos, a gorgeous-looking book by Ethan Siegel (intro by Brian Greene). It’s about the history of the JWST, humanity’s biggest ever space telescope, a machine that allows us to peer deeper & clearer into the universe than ever before, and some of the amazing results obtained through its use.
Siegel wrote a piece about the book for Big Think, which includes an excerpt. Gravitational lensing is so cool:
Even with its unprecedented capabilities, JWST’s views of the universe are still finite and limited. The faintest, most distant objects in the cosmos — including the very first stars of all — remain invisible even in the longest-exposure JWST images acquired to date. The universe itself offers a natural enhancement, however, that can reveal features that would otherwise remain unobservable: gravitational lensing.
Whenever a large amount of mass gathers together in one location, it bends and distorts the fabric of the surrounding space-time, just as the theory of general relativity dictates. As light from background objects even farther away passes close to or through that region of the universe, it not only gets distorted but also gets magnified and potentially bent, either into multiple images or into a complete or partial ring. The foreground mass behaves as a gravitational lens. The amount of mass and how it’s distributed affect the light passing through it, amplifying the light coming from those background sources.
Infinite Cosmos is available for purchase at Amazon and Bookshop.
Royal Museums Greenwich has announced the winners of the Astronomy Photographer of the Year 2024 competition. You can also check out some of the shortlist entries and runners-up in each category (Moon, Sun, etc.)
Photos above by (from top to bottom): Tom Williams, Peter Ward, Ryan Imperio, and Tom Rae.
Ok, I did not know this, and it’s blowing my mind: we have been imaging exoplanets for such a long time that scientists have made time lapse movies of their motion around their stars. This one is a 12-year time lapse of four planets orbiting a star called HR 8799 (images from 2009-2021):
And this one of Beta Pictoris b covers a time period of 17 years (2003-2020):
HR 8799 is 133.3 light-years away from Earth and Beta Pictoris is 63.4 light-years away. That’s amazing! (via @philplait.bsky.social)
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