Astronomy and Planetary Science Thread

Some more interesting news from Fraser Cain:


Lucy’s close up images of another asteroid, why Mars has a lopsided magnetic field, Chinese engineers rescue a pair of satellites with gravitational slingshots, and new hints about where Mars’s carbon dioxide atmosphere went. In our longer Space Bites+ on Patreon, a proposed human mission to both Mars and the asteroid Ceres.
00:00 Intro
00:24 LUCY flyby of asteroid Donaldjohanson
https://www.universetoday.com/article...https://www.youtube.com/redirect?ev...up-of-a-weirdly-shaped-asteroid&v=jQNFiTQORvM
02:01 Mars' magnetic field
https://www.universetoday.com/article...https://www.youtube.com/redirect?ev...ts-of-a-lopsided-magnetic-field&v=jQNFiTQORvM
03:55 Where did Mars' atmosphere go?
https://www.universetoday.com/article...https://www.youtube.com/redirect?ev...riosity-found-where-it-all-went&v=jQNFiTQORvM
05:29 China's satellite rescue
https://www.universetoday.com/article...https://www.youtube.com/redirect?ev...o-rescue-a-pair-of-satellites-1&v=jQNFiTQORvM
07:01 Vote results / @frasercain https://www.youtube.com/channel/UCogrSQkBJn1KF0N9I4oM7eQ/community/community
07:42 Bacteria mimicking multicellular life
https://www.universetoday.com/article...https://www.youtube.com/redirect?ev...t-can-mimic-multi-cellular-life&v=jQNFiTQORvM
09:29 Planet orbiting perpendicular to its stars
https://www.universetoday.com/article...https://www.youtube.com/redirect?ev...ndicular-orbit-around-two-stars&v=jQNFiTQORvM
11:10 Moon ejecta hitting Earth
https://arxiv.org/abs/2504.15502https://www.youtube.com/redirect?ev...ttps://arxiv.org/abs/2504.15502&v=jQNFiTQORvM
12:42 Cool images
https://www.universetoday.com/article...
https://www.universetoday.com/article...
https://www.esa.int/ESA_Multimedia/Im...https://www.youtube.com/redirect?ev...widest_high-res_view_of_the_Sun&v=jQNFiTQORvM
15:10 Guide to space
15:56 Space Bites+
16:19 Telescope updates
Host: Fraser Cain
Producer: Anton Pozdnyakov
Editing: Artem Pozdnyakov
 
Flyaway said:
In this episode, Dr. Nikku Madhusudhan of the University of Cambridge discusses a major breakthrough in the search for life beyond Earth. Using the James Webb Space Telescope, his team has detected the chemical fingerprints of dimethyl sulfide (DMS) and dimethyl disulfide (DMDS) in the atmosphere of K2-18 b. These compounds, which on Earth are associated mostly with biological activity, suggest that this distant potential Hycean world may be one of the most promising candidates for life outside our solar system. The findings open a new chapter in the study of habitable exoplanets and the search for extraterrestrial biology.

A very inspiring development, one would expect this being headline news all over. Godier, fortunately, proved to be an able interviewer and had good rapport with Madhusudhan. Too bad our political and business leaders (not to mention authoritarians) in their navel gazing (if not indeed a deeper exploration of their own lower intestines) have gotten us all in such a state that a discovery of a very likely biosphere in another star system is but a ripple in our new stream.

It was good to hear about Madhusudhan's meticulous and multi-pronged blind heuristic in getting to a result, especially as the statistical 3σ finding is strongly supported by both preceding and remaining future avenues of research. Beyond this, his qualitative analysis was very convincing. I've not listened to nearly everything Godier has put out but I know he has had a tentative notion of microbial life being quite common in the universe and thus his excitement for a promising candidate so close by was no surprise. Truly interesting.
 
Some major new discoveries concerning the origins of multi-cellular life on Earth, from Anton Petrov:


0:00 Origins of multicellular life
0:45 Eukaryotes vs prokaryotes
2:10 History of multicellular morphology
2:50 Why is there no multicellular bacteria?
3:45 Study that provides first hints - snowball Earth
7:00 Why some structures become permanent - viruses
8:20 Bacteria that's ALWAYS multicellular
10:35 Intriguing experiments and discoveries
12:00 Conclusions and what this means
 
Space models

I was hoping it would be more like…this

Sim
 
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From GEO GIRL:


Check out the part 1 Death Valley video about the geologic history of the region: • Geology of Death Valley- Hottest, Dry... https://www.youtube.com/watch?v=5OoG9IiKCoQ
Check out the video about Clay Minerals on Mars That May Indicate Past Water & Life: • Clay Minerals on Mars Indicate Past W... https://www.youtube.com/watch?v=7vBhk92CApc
 
Our galactic neighbor Andromeda has a bunch of satellite galaxies — and they're weirdly pointing at us

Our neighboring Andromeda Galaxy (Messier 31, or M31) appears to sport a lopsided arrangement of satellite galaxies that defy scientific models, stumping astronomers who are also trying to figure out why so many of this galaxy's family members point in our direction. All but one of M31's brightest 37 satellites are on the side of the Andromeda spiral that faces our Milky Way galaxy – the odd one out being Messier 110, which is easily visible in amateur images of the Andromeda Galaxy.



New simulations by Kanehisa, along with his Potsdam colleagues Marcel Pawlowski and Noam Libeskind, show that, according to cosmology's standard model, the odds of having such a lopsided arrangement are less than 0.3%. And yet, the closest galaxy to us is beating those odds. So when is a coincidence just a coincidence, and when does it open a window into a deeper mystery?



Accurate data regarding the motion of the dwarf galaxies is known for only four of M31's satellites (five if IC 10 is counted, which is a contested member of the M31 system), which means that simulations can be a little rough. However, astronomers are aiming to determine the motions for at least a dozen of M31's dwarfs to high precision within another year or two with the release of the next dataset from the Gaia astrometric mission.

"Once we have a more substantial sample of M31 dwarfs with proper motions, we should be better positioned to study the time evolution of the observed asymmetry," said Kanehisa. In other words, we would be able to better understand for how long this lopsided alignment can stay in place.


Related paper:

 

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