Astronaut Don Pettit is, among many other things, an amateur astronomer. One of the most delightful moments of my life with getting to hear him talk to National Geographic photographer Babak Tavarshi about the challenges of trying to image the sky from the International space station and asking to brainstorm solutions. Well, it looks like that conversation, and many more that I assume have also taken place, allowed Don to figure out how to get past some of the issues he was struggling with. On his Twitter feed, which I believe is being maintained by his son, a series of Don’s images from the ISS have been getting posted. on this trip, he took with him a homemade device for tracking the stars, while on the international space station. Hubble space telescope and other observatories use their reaction wheels to keep the entire satellite pointed correctly. In order to track well on the ISS, a completely different solution had to be found. Exactly what Don built, I’m hoping I can find out someday, but right now, the magical device’s details aren’t published.
While his image of the Milky Way appearing over the edge of the motion blurred Earth is getting attention as potentially the best photo ever taken from orbit, I have to say my favorite is a picture of the large and small Magellanic cloud framed in a window.
To my surprise, Starlink satellites are cropping up in his astrophotography with even more drama than we’re experiencing from here on the surface of the planet. Not only are they creating streaks in his images, but in videos they are putting on a truly dramatic light show. In a December 1 Tweet he writes, “cosmic fireflies. Actually, these are starlink satellites, momentarily flashing sunlight towards the space station.”
Amateur Astronomers redefine Jupiter’s banding
I want to be clear here, calling Don Pettit an amateur astronomer is anything but an insult. Amateur astronomers are awesome people who make the voluntary choice to do astronomy without getting paid. There are lots of professional astronomers, who, due to funding gaps, periodically find themselves involuntarily working as unpaid astronomers, but the amateur astronomers are out there doing this entirely by choice.
And these folks are periodically making really cool discoveries. One of the things that has been startling me over and over in recent years is the creativity of how amateur astronomers are using filters to get around light pollution and to reveal time consuming details that, as professional astronomers, we never get to see because we don’t have the same dedicated observing time that they have. In one creative use of filters, a Colorado team led by Steven Hill figured out how to combine observations from different filters used on an 11-inch telescope to map out methane and ammonia in the atmospheres of Jupiter and Saturn.
That alone is reason enough to share this cool result, but that’s not all. These results allowed the location of the ammonia clouds in Jupiter’s atmosphere to be refined, and it turns out those clouds are lower in the atmosphere than previously thought, which makes them warmer than previously thought, which means they aren’t made of ammonia ice as previously thought.
Their work initially appeared in the journal Earth and Space Science last August.
On January 1, a sister publication, the Journal of Geophysical Research: Planets, published a follow-up paper led by Patrick Irwin that confirmed these depth-defining results using ESO’s Very Large telescope. Where the first paper used an 11-inch or 0.28 meter telescope, VLT is an 8.2 meter or 323-inch telescope.
They confirmed those clouds are lower and thus hotter than thought. This means they can’t be ammonia ice, and are most likely ammonium hydrosulfide, which would provide the same colors at warmer temperatures. We now literally get to rewrite textbooks thanks to folks who spent their personal time and money to do some science.
New all-constellation maps
If you want to do your own explorations of the sky and just want to pour through images without having to pour out the money for telescopes, NOIRLab and ESA have an opportunity for you.
A new collection of imagery allows you to explore all 88 constellations. These free downloadable images are posted along with information on the constellation’s name, key features, and even finding charts to help you navigate either the image or the actual night sky. Also released is the largest open-source all-sky image. With 40,000 x 20,000 pixels, you are going to have to zoom in to appreciate its detail.