Astronomy and Planetary Science Thread

NASA has significantly lowered the risk of near-Earth asteroid 2024 YR4 as an impact threat to Earth for the foreseeable future. When first discovered, asteroid 2024 YR4 had a very small, but notable chance of impacting our planet in 2032. As observations of the asteroid continued to be submitted to the Minor Planet Center, experts at NASA Jet Propulsion Laboratory’s (JPL’s) Center for Near-Earth Object Studies were able to calculate more precise models of the asteroid’s trajectory and now have found there is no significant potential for this asteroid to impact our planet for the next century. The latest observations have further reduced the uncertainty of its future trajectory, and the range of possible locations the asteroid could be on Dec. 22, 2032, has moved farther away from the Earth.
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There still remains a very small chance for asteroid 2024 YR4 to impact the Moon on Dec. 22, 2032. That probability is currently 1.7%.
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Latest Calculations Conclude Asteroid 2024 YR4 Now Poses No Significant Threat to Earth in 2032 and Beyond – Planetary Defense

blogs.nasa.gov blogs.nasa.gov
 
Mars Is Red, But Maybe Not For The Reasons We Thought

A new study has found evidence that Mars's red color may not be caused by the mechanism scientists once thought. The discovery hints at a potentially more habitable past for the Red Planet.
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…

A new study combining spacecraft observations and laboratory experiments may change this view, suggesting that the planet is red due to the presence of ferrihydrite. This is a pretty big deal, as ferrihydrite forms quickly in the presence of cool water, suggesting that Mars gained its hue when the planet still had an abundance of water at its surface.
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www.iflscience.com

Mars Is Red, But Maybe Not For The Reasons We Thought

A new study recreating Martian soil hints that Mars's history may be more exciting than we thought.
www.iflscience.com www.iflscience.com

Related paper:

www.nature.com

Detection of ferrihydrite in Martian red dust records ancient cold and wet conditions on Mars - Nature Communications

Mars’ distinctive red colour attributed to ferrihydrite, a type of rust mineral. This finding suggests Mars experienced a cold and wet environment before transitioning to its current desert state.
www.nature.com www.nature.com
 
Flyaway said:
Mars Is Red, But Maybe Not For The Reasons We Thought



…



www.iflscience.com

Mars Is Red, But Maybe Not For The Reasons We Thought

A new study recreating Martian soil hints that Mars's history may be more exciting than we thought.
www.iflscience.com www.iflscience.com

Related paper:

www.nature.com

Detection of ferrihydrite in Martian red dust records ancient cold and wet conditions on Mars - Nature Communications

Mars’ distinctive red colour attributed to ferrihydrite, a type of rust mineral. This finding suggests Mars experienced a cold and wet environment before transitioning to its current desert state.
www.nature.com www.nature.com
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It must have had water, possibly from comets, such as that found in the shaded areas of the lunar poles. When the magnetic field weakened, the solar wind carried away the old atmosphere and the iron on the surface oxidized.
 
There could be a supermassive black hole in the Large Magellanic Cloud hurling stars at the Milky Way

Hypervelocity stars (HVSs) were first theorized to exist in the late 1980s. In 2005, the first discoveries were confirmed. HVSs travel much faster than normal stars, and sometimes, they can exceed the galactic escape velocity. Astronomers estimate that the Milky Way contains about 1,000 HVSs, and new research shows that some of these originate in the Milky Way's satellite galaxy, the Large Magellanic Cloud (LMC).
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New research submitted to The Astrophysical Journal shows that a surprising number of the Milky Way's HVSs come not from the galactic center but from the LMC. It's titled "Hypervelocity Stars Trace a Supermassive Black Hole in the Large Magellanic Cloud." The lead author is Jiwon Han, a grad student at the Harvard and Smithsonian Center for Astrophysics who studies galactic archaeology, and it is available on the arXiv preprint server.
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phys.org

There could be a supermassive black hole in the Large Magellanic Cloud hurling stars at the Milky Way

Hypervelocity stars (HVSs) were first theorized to exist in the late 1980s. In 2005, the first discoveries were confirmed. HVSs travel much faster than normal stars, and sometimes, they can exceed the galactic escape velocity. Astronomers estimate that the Milky Way contains about 1,000 HVSs...
phys.org

Related paper:

Hypervelocity Stars Trace a Supermassive Black Hole in the Large Magellanic Cloud

Hypervelocity stars (HVSs) are produced by the Hills mechanism when a stellar binary is disrupted by a supermassive black hole (SMBH). The HVS Survey detected 21 unbound B-type main-sequence stars in the Milky Way's outer halo that are consistent with ejection via the Hills mechanism. We revisit...
arxiv.org arxiv.org
 
NMaude said:
I wonder if Mira qualifies as an HVS? It does move through interstellar space at a fair clip IIRC.
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The only theorized mechanism for the acceleration of these stars is the capture of a double star by the gravitational field of a black hole that ends with the ejection of one of them because of the rupture of the pair of forces.

But perhaps there are other mechanisms to obtain the same result without the existence of a black hole inside a globular cluster.

www.wired.com

Something Unexpected Is Spewing Stars Into the Milky Way

Fast-moving stars in the Milky Way indicate there could be a supermassive black hole in the neighboring Large Magellanic Cloud—something that has never been detected in a smaller galaxy.
www.wired.com www.wired.com
 
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Solar system's journey through Orion complex 14 million years ago may have altered Earth's climate

An international research team led by the University of Vienna has discovered that the solar system traversed the Orion star-forming complex, a component of the Radcliffe Wave galactic structure, approximately 14 million years ago. This journey through a dense region of space could have compressed the heliosphere, the protective bubble surrounding our solar system, and increased the influx of interstellar dust, potentially influencing Earth's climate and leaving traces in geological records.
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phys.org

Solar system's journey through Orion complex 14 million years ago may have altered Earth's climate

An international research team led by the University of Vienna has discovered that the solar system traversed the Orion star-forming complex, a component of the Radcliffe Wave galactic structure, approximately 14 million years ago. This journey through a dense region of space could have...
phys.org phys.org

Related paper:

The Solar System’s passage through the Radcliffe wave during the middle Miocene | Astronomy & Astrophysics (A&A)

Astronomy & Astrophysics (A&A) is an international journal which publishes papers on all aspects of astronomy and astrophysics
www.aanda.org www.aanda.org
 
GeologyHub has put out a short video about the potential impact of 2024YR4 on the Moon:


On December 22nd, 2032, there is a chance that a nearly mile wide crater might suddenly form on the moon which momentarily creates a source of light brighter than the full moon. This might occur due to the impact of a 55 meter wide asteroid known as 2024 YR4, which through recent observations has been proven essentially unable to impact Earth. However, there is a 1.7% chance it will impact our moon on that date, releasing the equivalent amount of energy 4.7 million tons of TNT has. Today's video will discuss this asteroid, its size, and give a broader context and analysis about what might happen next.
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Thumbnail Photo Credit: This work "BroadMoon1", is a derivative of a photo (resized, cropped, brightened the image in shadowed/darker areas, reduced the image's original color temperature, text overlay, GeologyHub made graphics (the image border & the GeologyHub logo)) from "Shot of a half-ish moon over Rockville, MD using a variety of teleconverters", by: John Brighenti, alchemist_x, 2018, Posted on Flickr, Flickr account link: https://www.flickr.com/photos/alchemi..., Photo link: https://www.flickr.com/photos/alchemi..., CC BY 2.0. "BroadMoon1" is used & licensed under CC BY 2.0 by / geologyhub https://youtube.com/GeologyHub
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Estimates on asteroid diameter, velocity, tnt energy equivalent, frequency of a similar magnitude asteroid/comet impact event, and effects from the impact (including earthquake magnitude generated, ejecta thickness, thermal radiation, and wind speeds generated) in this video were sourced using the calculator at https://impact.ese.ic.ac.uk/ImpactEar..., which was used with permission.
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Sources/Citations:
[1] NASA
[2] Sentry: Earth Impact Monitoring, https://cneos.jpl.nasa.gov/sentry/, "(2024 YR4)"
[3] Morrison, D., Chapman, C. R., Steel, D., and Binzel R. P. “Impacts and the Public: Communicating the Nature of the Impact Hazard” In Mitigation of Hazardous Comets and Asteroids, (M.J.S. Belton, T.H. Morgan, N.H. Samarasinha and D.K. Yeomans, Eds), Cambridge University Press, 2004.
[4] Peter Jenniskens, Olga P. Popova, Dmitry O. Glazachev, Elena D. Podobnaya, Anna P. Kartashova, Tunguska eyewitness accounts, injuries, and casualties, Icarus, Volume 327, 2019, Pages 4-18, ISSN 0019-1035, https://doi.org/10.1016/j.icarus.2019.... (https://www.sciencedirect.com/science...)
[5] Yastrebov, A. (2022) Substantiation of the Western Trajectory of the Tunguska Cosmic Body. Natural Science, 14, 171-185. doi: 10.4236/ns.2022.145017.
[6] G. Collins & others, "A numerical assessment of simple airblast models of impact...", Meteoritics & Planetary Science https://doi.org/10.1111/maps.12873 (2017), CC BY 4.0
[7] ESO/O. Hainaut et al., European Southern Observatory, https://www.eso.org/public/videos/YR4-2/https://www.youtube.com/redirect?event=video_description&redir_token=QUFFLUhqbVNtelRMUkdONy1HeGpHdEtvSVIyOEZYVWhVQXxBQ3Jtc0trUk8xam1WaWVkcEp0WW4yS2doZlpueFo1S3hzaG82VXhacDRJV0FzbnlSX0JmSFVHOTVmTFhLOXQ4TzlpLS1XSTJuR0dfSnMwR3NaWkFzczN4d05pUTY0UHZxMGR1ei1PM0xEOHZjYThmUzA3dWJuZw&q=https://www.eso.org/public/videos/YR4-2/&v=qMlnvf--TrU
[8] European Southern Observatory
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0:00 Good News
0:18 2024 YR4 Update
1:38 Possible Trajectories
2:39 Near Earth Objects
3:28 Rate of Similar Impacts
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A new study published in PNAS today has made quite a splash. The study involved a team of Chinese and American scientists led by Jianhui Li from Guangzhou University in China, and was based on work done by the China National Space Administration’s Mars rover Zhurong.

Data from Zhurong provide an unprecedented look into rocks buried near a proposed shoreline billions of years old. The researchers claim to have found beach deposits from an ancient Martian ocean.
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theconversation.com

Scientists have discovered a 3 billion-year-old beach buried on Mars

The discovery indicates water may have remained stable on Mars for much longer than scientists thought.
theconversation.com theconversation.com

Related paper:

 
No mistake, in my opinion - for the sake of completeness :)
 
A volcano erupted in Central America tens of thousands of years ago, creating an explosion so enormous that scientists believed it triggered prolonged enough global cooling to kick off an ice age. Known today as the Los Chocoyos supereruption, it was one of the largest of the Quaternary period, but a new study looking at ancient ice cores paints a very different picture of what came next.
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www.iflscience.com

One Of Earth’s Largest Known Supereruptions Dramatically Altered The Climate 79,500 Years Ago

But ice core analysis has revealed surprising insights as to how quickly the planet bounced back.
www.iflscience.com www.iflscience.com

Related paper:

www.nature.com

Ice core evidence for the Los Chocoyos supereruption disputes millennial-scale climate impact - Communications Earth & Environment

The climate system was resilient over the Atitlán Los Chocoyos volcanic supereruption, one of the largest in the Quaternary, which occurred approximately 79,500 years ago, according to Greenland and Antarctic ice core evidence
www.nature.com www.nature.com
 
It looks like the biggest known star (WOH G64) might be going boom in the near future in a Type-II core-collapse supernova, from Anton Petrov:


Hello and welcome! My name is Anton and in this video, we will talk about a potential nearby supernova of a star WOH G64
Links:
https://www.researchsquare.com/articl...https://www.youtube.com/redirect?ev...quare.com/article/rs-5551282/v1&v=gHvV9ewPY7s
https://www.eso.org/public/images/eso...https://www.youtube.com/redirect?ev...eso.org/public/images/eso2417b/&v=gHvV9ewPY7s
Recent video about this star: • Unexplained Observations From the Lar... https://www.youtube.com/watch?v=fcPVfQLCZmc&t=0s
#wohg64 #supernova #astronomy
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0:00 Major chance for a visible supernova soon!
0:55 What star is this? WOH G64
2:05 Why this star is bizarre and why it shocked scientists
6:00 Major changes that have never been seen before
6:55 Supernova? Maybe but...
8:35 Conclusions and what's next?
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So what will be the end result of a core collapse supernova? Black Hole or neutron star, I would think a black hole if WOH G64's core is big enough to collapse into a black hole. Remember that the star that blew up into SN-1987A was half the mass of this star and that ended up as a neutron star.
 
FighterJock said:
So what will be the end result of a core collapse supernova? Black Hole or neutron star, I would think a black hole if WOH G64's core is big enough to collapse into a black hole.
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I'm not an astrophysicist but IIRC if the star is 20-25 solar-masses then the core will collapse into a blackhole.
 
Is there any new theory that explains where all the material that absorbs a black hole goes? Parallel universes? White holes arising elsewhere? I'm a little old-fashioned with my reading... any ideas?
 
It looks like a mystery may've just been solved, from Anton Petrov:


Hello and welcome! My name is Anton and in this video, we will talk about Little Red Dots discovered by the James Webb Space Telescope
Links:
https://arxiv.org/abs/2409.06772https://www.youtube.com/redirect?ev...ttps://arxiv.org/abs/2409.06772&v=V2G5IR9gAqI
https://iopscience.iop.org/article/10...https://www.youtube.com/redirect?ev...rticle/10.3847/2041-8213/ad5669&v=V2G5IR9gAqI
Previous video:
https://www.youtube.com/watch?v=xkdAbOS9AcA&t=0s
• Nobody Can Explain 1000s of Strange L...

• Discovery of Green Pea Galaxies by JW... https://www.youtube.com/watch?v=7u-MTgYSSI4&t=0s
#jameswebbspacetelescope #quasar #galaxy
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0:00 One of the biggest JWST mysteries - Little Red Dots
2:00 Why were they breaking cosmological concepts?
3:15 Possible explanation - overmassive black holes?
4:30 Why so red?
5:10 Almost certain explanation from recent studies
7:20 Biggest evidence that these are black holes
9:45 Additional questions
10:50 More explanations for why they look this way
11:40 But still some problems left
12:10 Green peas comparison
12:50 Conclusions
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An international team of researchers has discovered that previously observed variations in brightness of a free-floating planetary-mass object known as SIMP 0136 must be the result of a complex combination of atmospheric factors, and cannot be explained by clouds alone.
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science.nasa.gov

NASA’s Webb Exposes Complex Atmosphere of Starless Super-Jupiter - NASA Science

An international team of researchers has discovered that previously observed variations in brightness of a free-floating planetary-mass object known as SIMP
science.nasa.gov science.nasa.gov
 
So what happened to the planet that is free floating? Got kicked out of it's home solar system?
 
FighterJock said:
So what happened to the planet that is free floating? Got kicked out of it's home solar system?
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They'll get back to you on that in a couple of years.

https://en.wikipedia.org/wiki/Rogue_planet

Rogue planets may originate from planetary systems in which they are formed and later ejected, or they can also form on their own, outside a planetary system. The Milky Way alone may have billions to trillions of rogue planets, a range the upcoming Nancy Grace Roman Space Telescope is expected to refine.

Some planetary-mass objects may have formed in a similar way to stars, and the International Astronomical Union has proposed that such objects be called sub-brown dwarfs. A possible example is Cha 110913−773444, which may either have been ejected and become a rogue planet or formed on its own to become a sub-brown dwarf.
 
Water, the key ingredient for life, found to have formed shortly after the Big Bang

New research suggests the essential ingredient for life could have emerged billions of years earlier than previously believed
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www.port.ac.uk

Water, the key ingredient for life, found to have formed shortly after the Big Bang

New research suggests the essential ingredient for life could have emerged billions of years earlier than previously believed
www.port.ac.uk www.port.ac.uk

Related paper:

Nature Astronomy

Nature Astronomy is a truly multidisciplinary journal for the field, representing — and fostering closer interaction between — all of the key ...
www.nature.com www.nature.com
 
An interesting find Flyaway, that will blow away the theory that water formed much later than the Big Bang.
 

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