6 comments

  • _Microft 4 days ago

    The paper is open access and contains lots of pictures, so at leasts we non-geologists got something nice to look at.

    https://www.nature.com/articles/s41598-020-75665-7

    • vogtb 4 days ago

      For anyone interested in Mars geology, I highly recommend Kim Stanley Robinson's "Mars" sci-fi trilogy. It has an astounding amount of detail that is largely realistic.

      • JumpCrisscross 4 days ago

        Robinson’s use of “escarpment” rivals Ian M. Banks’ of “whorls”.

        Jesting aside, it’s a beautiful series. The landscape descriptions sometimes get tedious. But you find yourself missing the old land as the series progresses, an effect woven brilliantly.

        • How did Banks use "whorls"? I don't remember. I remember him using "escarpment" often, e.g. in The Bridge I think, and also in the "escarpment class" (in the culture novels).

          • JumpCrisscross 3 days ago

            > How did Banks use "whorls"?

            Every atmosphere was whorly. The clouds on Vavatch—that’s when I looked it up. The air whale planet is the last one I remember reading it in respect of.

            • Huh. I didn't remember that.

              To be fair, I had to look up Vavatch. It's been a while since I read the last Banks book. And it really was the last :(

          • arethuza 3 days ago

            "The landscape descriptions sometimes get tedious."

            I find the KSR's descriptions of landscapes one of the best bits of all of his books.

        • Konohamaru 4 days ago

          Strange how Mars had a planetary-round flood but Earth didn't.

          • I'm not sure that's the case. I think there's been some times (like maybe pre-Devonian), where the Earth was pretty much Waterworld.

            There was a series of books that Terry Pratchett co-authored, called The Science of Discworld, where a bunch of wizards were creating a planet, and it went through a bunch of phases, punctuated by E.L.E. asteriod impacts. I think it was a fanciful chronicle of early Earth.

            Interesting books.

            • IanCal 4 days ago

              I avoided those books for a long time as I thought they were going to be made up explanations for how things worked in the Discworld. They're actually a wonderful set of stories and jumping off point for discussing a variety of topics. Heavily recommend them to people who may have been in the same position as me.

              • ZeroGravitas 3 days ago

                Yes, they're a good mix of Pratchett content and well written popular science coverage of concepts.

                As well as the science ones there a Folklore of Discworld which could easily have been a throwaway novelty but was a great unsight into the real folklore that Pratchett references and lampoons.

            • rement 4 days ago

              Some scientist hypothesize that millions of years ago the Earth's surface completely froze over. It is called snowball earth [0].

              [0] https://en.wikipedia.org/wiki/Snowball_Earth

              • cultus 4 days ago

                The geologic evidence for Snowball Earth (multiple ones, actually) is extremely strong. It is almost impossible to explain the re-emergence of banded iron formations without it.

                The hard part is explain is how photosynthetic life survived. The Slushball Earth hypothesis holds that there was a band of thin ice near the equator. This has some severe problems though. For one, it isn't climatologically stable. The oceans in SE were covered by "sea glaciers," which were floating glaciers thicker near the poles, which flowed to the equator. These flowed due to the weak hydrologic cycle, with ice experience net sublimation near the equator. These would have overridden any areas of thin or nonexistent ice.

                A hypothesis that is getting more traction is that narrow equatorial rift seas (like the Red Sea) would have prevented inflow of the sea glaciers enough for thin-ice refuges to exist. These kind of seas probably existed, because this was occurring as the supercontinent Rodinia was beginning to break up.

                • kwk1 4 days ago

                  > A hypothesis that is getting more traction is that narrow equatorial rift seas (like the Red Sea) would have prevented inflow of the sea glaciers enough for thin-ice refuges to exist.

                  Wow, that makes imagining conditions on the Snowball Earth all the more fascinating, thank you.

              • grey_earthling 4 days ago

                75% of Earth's surface is still flooded :)

                • Konohamaru 4 days ago

                  Geologists generally speaking don't know how the ocean emerged, but all agree it wasn't due to a catastrophic deluge.

                  • eloff 4 days ago

                    At least after formation, but also likely again after the impact thought to produce the moon, all the surface was melted, so all the water was in the atmosphere and inside the Earth. When things cooled enough for liquid water to rain down and stay liquid, that must have been some deluge.

              • cabite 3 days ago

                Randall Carlson thinks it happened on Earth, around 10,000 years ago.

                Mega-ripples of Camas Prairie Basin

                https://www.youtube.com/watch?v=3iNHQCKQNhY

                • briefcomment 4 days ago

                  Noah crossed to the earth on his spaceship ark :D

                  • bigbubba 4 days ago

                    I'm intrigued by the premise that humans are aliens who've forgotten our own origin, but unfortunately the fossil record debunks this. We're definitely from earth, at least since our very distant microbial ancestors.

                • dmead 4 days ago

                  I just stayed up all night imaging mars from my back yard. This makes me wanna go do it again :)

                  • gnatman 4 days ago

                    Any results you can share?

                    • dmead 2 days ago

                      not yet! i had major focus issues.