Printable Version of Topic

Click here to view this topic in its original format

Unmanned Spaceflight.com _ Mars _ Mars lakes and Marsquakes

Posted by: TheAnt Dec 14 2014, 02:34 PM

Cartography work carried out by http://www.usgs.gov/blogs/features/usgs_top_story/new-usgs-map-of-mars-is-most-detailed-one-yet/ have revealed further proof of ancient lake beds and signs of Mars-quakes in the Valles marineris region.

A shorter pressrelease from http://www.jpl.nasa.gov/news/news.php?feature=4408.

Posted by: TheAnt Dec 2 2016, 08:14 AM

Warming by asteroid impacts might yield a too transient warming to explain the erosion seen on Mars, now http://news.psu.edu/story/440075/2016/12/01/research/climate-cycles-may-explain-how-running-water-carved-mars-surface created somewhat warmer longer periods that could explain how running water carved Mars' surface.

Posted by: TheAnt Feb 9 2017, 07:43 PM

CNRS, Laboratoire de Planétologie et Géodynamique de Nantes, France: https://planetarygeomorphology.wordpress.com/2013/09/16/moraines-left-by-carbon-dioxide-glaciers-on-mars/.

Posted by: atomoid Feb 9 2017, 11:02 PM

QUOTE (TheAnt @ Dec 2 2016, 12:14 AM) *
Warming by asteroid impacts might yield a too transient warming to explain the erosion seen on Mars, now http://news.psu.edu/story/440075/2016/12/01/research/climate-cycles-may-explain-how-running-water-carved-mars-surface created somewhat warmer longer periods that could explain how running water carved Mars' surface.

interesting.. reinvigorates the uncertainty around assumptions raised by the Feb 6th 'https://www.nasa.gov/feature/jpl/nasas-curiosity-rover-sharpens-paradox-of-ancient-mars' which seems to suggest ruling out past acidity as a candidate for possible carbonate sequestration, at least in the Gale deposits.

Posted by: serpens Feb 10 2017, 03:05 AM

It seems that analysis of ancient rocks on both Earth and Mars has provided no evidence of greenhouse gasses as an explanation for warm wet environments under a faint young sun. When empirical evidence clashes with modelling it is prudent to re-evaluate the assumptions underpinning the model. One hypothesis that I find of interest is the possible effects of the solar system passing through interstellar dust clouds. There would be minimal attenuation of solar flux but the capture of molecular hydrogen would result in a significant increase in the sun's luminosity. McCrea, W.H. (1975). Ice Ages and the Galaxy, Nature 255, 607–609 suggests that an encounter with interstellar cloud densities of 10^5 to 10^7 H2/cm3 would increase the Sun’s luminosity by up to 100 percent during the course of an encounter.

Posted by: TheAnt Oct 29 2017, 06:31 PM

https://www.alphagalileo.org/ViewItem.aspx?ItemId=180388&CultureCode=en
Yes boiling, due to the very low air pressure, if the temperature get high enough to melt any ice the liquid water will instantly start to boil.

Posted by: serpens Nov 8 2017, 11:29 PM

More likely any exposed ice would sublimate , Phoenix trench "Dodo-Goldilocks" for example.

Posted by: JRehling Nov 9 2017, 04:11 PM

Relatively small changes in conditions can lead to important changes in dynamics. An ancient Mars with slightly higher surface pressure would enable a liquid phase of matter.

However, it's not only different climates that allow this. Mars has higher subsurface pressure now than its surface pressure now. Water ice with a bit of regolith on top of it can reach conditions that allow a liquid phase. Boiling of that water would create rapid expansion that would move that regolith while relieving the pressure that enabled the liquid phase in the first place. Slightly different climates could allow profoundly different dynamics. There are a lot of variables to contend with.

Powered by Invision Power Board (http://www.invisionboard.com)
© Invision Power Services (http://www.invisionpower.com)