from the lab-experiments-with-martian-analogue-soils dept.
Martian landslides may be caused by melting ice and salt under the surface:
The NASA InSight mission has helped researchers determine that the planet experiences Marsquakes, making it seismically active.
And then there is the mystery of Recurring Slope Lineae, known as RSL, that have intrigued scientists for years. These RSL are a form of landslide on Mars, but no one knows what causes them, said Janice Bishop, author of a new study on the phenomena.
"We see them from orbit by the dark streaks they produce on the ground and they tend to always occur on sun-facing slopes, which led geologists to think they were related to melting ice early on," said Bishop, senior research scientist at the SETI Institute in California.
"The interesting thing is that they increase over months following dust storms and then fade away, and they appear to form repeatedly in the same regions. Also, a large number of these are forming in the equatorial part of Mars, where there is very little ice."
[...] These puzzling landslides have never been seen up close by a rover or lander, and until they can be investigated by a robotic explorer, scientists are using lab experiments and Martian analogs on Earth to try and understand them.
[...] "If our hypothesis is correct, then RSL could be indicators for salts on Mars and for near-surface active chemistry," Bishop said. "Most of us Mars scientists have considered modern Mars as a cold and dry and dormant place, shaped mostly by dust storms. This is certainly true of the surface, but our work shows that the subsurface could be much more chemically active than realized before."
Journal Reference:
J. L. Bishop, M. Yeşilbaş, N. W. Hinman, et al. Martian subsurface cryosalt expansion and collapse as trigger for landslides [open], Science Advances (DOI: 10.1126/sciadv.abe4459)
(Score: 2) by jb on Sunday February 07 2021, @04:16AM
How could it possibly mean anything else? ;)
(Score: 4, Insightful) by Socrastotle on Sunday February 07 2021, @04:36AM (5 children)
In the late 19th century the first detailed observations of Mars were made. And in these observations we saw linear surface characteristics that appeared to be something like canals. It was thought that these were probably manmade water/irrigation passages to transit water across a barren planet. Further observation revealed this to be false.
Zooming forward from this pattern of observation of refutation we can get all the way to 2013. Before 2013 we naturally thought Mars' surface was dry and inhospitable because it look, from our vantage point, like a desert. In the movie/book "The Martian", one of the tasks the protagonist has to solve is finding water, and so he resorts to MacGyver type antics. In reality it's all much easier because it turns out [space.com] that the surface is actually relatively moist. The top-level soil is, on average, about 2% water by weight. Heat up a foot of soil, get a liter of water out. And this discovery only took us 60 years of probes and rovers to make....
'Remote exploration' isn't exploration, or even discovery. It can help us get a broadly bigger picture, but what we can discover is just horribly limited. The first humans on Mars will, within a matter of weeks, end up revolutionizing what we thought we knew about the planet. And I'm quite anxious to see what their discoveries are. There's only one way forward.
(Score: 0) by Anonymous Coward on Sunday February 07 2021, @10:34AM (2 children)
That mars mission money could be better spent on the government redistributing wealth to itself though.
(Score: 0) by Anonymous Coward on Sunday February 07 2021, @12:33PM (1 child)
What your simplistic view fails to appreciate is that none of that money goes to Mars. It is all spent right here on Earth.
(Score: 0) by Anonymous Coward on Sunday February 07 2021, @01:38PM
But not by, to or for members of the government!
It being spent or not is irrelevant as long as it does not line the correct pockets.
(Score: 0) by Anonymous Coward on Sunday February 07 2021, @02:06PM (1 child)
> a foot of soil, get a liter of water out
journalist spotted(grin)
I think you meant to write something more like this?
+ take a cubic meter of soil, get 20 liters of water out.
(Score: 0) by Anonymous Coward on Sunday February 07 2021, @03:47PM
Please. What is that in football fields?
(Score: 2) by VLM on Sunday February 07 2021, @07:21PM (1 child)
Above the angle of repose land flows like water, well, chunky viscous liquid, but you get the idea. It varies a lot with environmental conditions on earth, a little water or a micro-earthquake and you get quite a landslide.
Angle of repose on other planets has always been entertaining to read about. Fun to watch the experimentalists try to analyze actual pictures vs the theorists doing all kinds of interesting simulations.
It seems the angle of repose does vary on other planets but its within a range not much bigger than the error range. Air pressure (or what passes for air) seems to be a much bigger effect than gravity.
(Score: 0) by Anonymous Coward on Sunday February 07 2021, @09:19PM
Story:
Years ago I visited a grad student friend after the end of the spring term. He made a point of taking me into the next office, recently vacated by another grad student who had already left for the summer. The desk had a random pile of papers against the back wall, 4+ feet high. My friend noted that it was at the angle of repose, it wasn't possible to add any more paper, it would just slide off.
(Score: 0) by Anonymous Coward on Monday February 08 2021, @12:18AM
Once the conditions are right, they will be set free and move to Earth for their feasting of flesh.
(Score: 3, Interesting) by ChrisMaple on Monday February 08 2021, @06:32PM
There are 2 ways to look at this melting on Mars
Humorous: Martian warming is the fault of humanity, it's all those polluting rovers causing Martian climate change.
Serious: Mars is warming without significant input from humans. The same thing that causes Martian warming (the sun) causes warming on Earth.