Arthur T Knackerbracket has processed the following story:
An international team of researchers has revealed evidence of bygone “vacation-style” sandy beaches on Mars: underground rock layers that testify to an ancient northern ocean with gently lapping waves, as detailed in a study published January 14 in the journal PNAS. Their work bolsters previous research suggesting that Mars once hosted large bodies of water and a potentially habitable environment.
“We’re finding places on Mars that used to look like ancient beaches and ancient river deltas,” Benjamin Cardenas, a geologist at Pennsylvania State University and a co-author of the study, said in a university statement. “We found evidence for wind, waves, no shortage of sand—a proper, vacation-style beach.”
Cardenas and his colleagues studied geological data collected by the Chinese Zhurong rover in 2021 in an area of Mars called Utopia Planitia. Zhurong comes equipped with ground-penetrating radar, a tool that “gives us a view of the subsurface of the planet, which allows us to do geology that we could have never done before,” said Michael Manga, a planetary scientist at the University of California, Berkeley, who also participated in the study.
The radar data revealed underground rock layers bearing a striking resemblance to geological structures on Earth called “foreshore deposits”—downward sloping formations shaped by water currents pulling sediments into oceans. The researchers confirmed the similarities by comparing the Mars data to radar images of Earthly coastal deposits—even the angles of the underground Martian slopes aligned with those on our planet.
“This stood out to us immediately because it suggests there were waves, which means there was a dynamic interface of air and water,” Cardenas explained. “When we look back at where the earliest life on Earth developed, it was in the interaction between oceans and land, so this is painting a picture of ancient habitable environments, capable of harboring conditions friendly toward microbial life.”
After making sure that the formation couldn’t be explained by other factors such as rivers, wind, or volcanic activity, the researchers suggest that the Martian formations, as well as the thickness of their sediments, imply the presence of a bygone oceanic coast.
[...] If Mars really had oceanfront property, its ancient shores might be some of the best places to hunt for signs of past life. Future missions could help settle the question: Did microbes once call these beaches home, or were they just waves rolling over an empty, lifeless world?
(Score: 3, Funny) by Gaaark on Monday March 10, @01:01AM (1 child)
Send Musk to his favourite place (Mars), and Trump can go with him to get a more natural orange-ness.
They'll have to go without suits and helmets, though... but they haven't been vaccinated so they should be okay.
--- Please remind me if I haven't been civil to you: I'm channeling MDC. I have always been here. ---Gaaark 2.0 --
(Score: 5, Funny) by looorg on Monday March 10, @01:52AM
Mars-a-Lago. Home of the galactic golf open.
(Score: 5, Interesting) by bzipitidoo on Monday March 10, @03:27AM (3 children)
I bet that Mars never had any life. If it did once have microbial life that is anything like Earthly microbial life, I'd think there would be stromatolites. It's possible there are fossil stromatolites, and our explorations have so far failed to find them. A thorough examination of ancient Martian coastlines should definitively answer that question, but I am guessing there are none to be found.
I also suspect that excepting Earth, the whole solar system is and always was lifeless. No germs in Europa's subsurface ocean, or anywhere else within our solar system.
Extra-solar planets, now that's the question. Since the discovery in the 1990s of the first extra-solar planet, 51 Pegasus b, we have found many, and can suppose our solar system is rather average in that regard. Getting into Drake Equation questions, but I suspect an important factor is the jump from microbial to multicellular. Maybe life started on 1 planet in 0.1% of solar systems, and in 90% of those cases, died out before ever evolving beyond the microbial. Mars may not be one of those cases, may have always been lifeless, but if deceased microbial life is as common as nearly 0.1% of solar systems, maybe Mars did once have life.
(Score: 2, Informative) by Anonymous Coward on Monday March 10, @02:45PM (2 children)
I think you're right about the step from single to multi cellular, but not about the difficulty of starting life. Earth got microbes just about as soon as it cooled down enough for them to survive. If a planet is in an orbit that gives it liquid water, then I think life is extremely likely.
Regarding the Fermi question, I think it is the cumulative effect, including a couple of sociological ones that Drake didn't put in his equation.
(Score: 2) by bzipitidoo on Monday March 10, @06:15PM (1 child)
Earth is practically a double planet. I recall reading that the Moon gives Earth rotational stability, and that this may have been one of the crucial factors for life. An Earth-like world without a big moon can suffer big and sudden tilts of its axis of rotation, with devastating effects for any life that may have arisen. Perhaps double planets are exceedingly rare. Pluto is a double dwarf planet, but that may not be representative of full planets.
You may be right about life arising fairly easily. Maybe the difficult part is hanging on for billions of years.
One thing to ponder about Earthly life: it's all related. If life is so easily started, why are there not 2 or more completely unrelated families on Earth? Did life arise several times, and fight to the death, until only one family was left? Did the other families die not from the competition but for other reasons? Just not very fit? I am guessing there were not multiple families, and it's because abiogenesis is not common nor easy.
(Score: 1) by khallow on Monday March 10, @06:43PM
Hmm, Earth has a fairly large axial tilt [wikipedia.org] relative to the orbital plane of the planet. Venus and Uranus are the only two planets with significantly bigger tilts. Venus has a slow retrograde rotation but otherwise lines up neatly perpendicular to the orbital plane (just in the opposite direction due to its retrograde motion. Uranus is on its side.
Anyway, what I see is a lot of planets with low axial tilt and the Earth, which is supposedly most stable, having a substantial tilt. So I don't think reality matches this hypothesis well.
i think there's a simple explanation. Once one group of organisms came up with a significant enough advance - like cell walls, chlorophyl, or nuclei it crowded out any potential competitors from evolving a parallel scheme.