Mars and the dim sun paradox

[Moontanman]

In the distant past our Sun was much dimmer than it is today, the science on this is pretty much confirmed, Faint sun paradox , during this time the Earth is thought to have had a large amounts of CO2 and Methane in its atmosphere to allow the Earth to have liquid water on its surface. On the other hand Mars is considered by many as too small to have had such an extensive atmosphere.

I am proposing that Mars was an ice world similar to Jupiter's Moon Callisto but much larger. Being an ice encased moon would allow for liquid water at the surface with a very thin atmosphere. As the magnetic field of Mars was lost the Solar Wind would have swept the atmosphere of Mars away and slowly stripped away the ice by photo desiccation of the ice shell of Mars. This would have resulted in the surface being eroded by water while the ice shell was intact and as the ice shell was eroded and swept away the surface of Mars would have become the dessicated surface we see but with evidence of water flowing as well. Much like water flowing beneath a glacier on earth but on a much larger scale. 

The would allow for the faint young sun and the evidence of liquid water on Mars.    

[spartan45]

3 hours ago, Moontanman said:

As the magnetic field of Mars was lost the Solar Wind would have swept the atmosphere of Mars away and slowly stripped away the ice by photo desiccation of the ice shell of Mars.

I am not sure a magnetic field is necessary to protect a planet’s atmosphere. Venus is subject to a stronger Solar Wind and has no magnetic field so the Solar Wind might be expected to have swept away its atmosphere and yet it is far denser than that of Earth. That said, the closer proximity to the Sun may have allowed a runaway greenhouse effect on Venus to create a very thick atmosphere easily able to deflect the stronger Solar Wind.

With respect to Mars; I wouldn’t be surprised if a comet scarred the Martian surface and took much of the atmosphere with it – not the solar wind. In fact the Solar wind appears to help protect the Solar system from dangerous highly energetic cosmic Rays from outside the Solar system.

[Moontanman]

6 hours ago, spartan45 said:

I am not sure a magnetic field is necessary to protect a planet’s atmosphere. Venus is subject to a stronger Solar Wind and has no magnetic field so the Solar Wind might be expected to have swept away its atmosphere and yet it is far denser than that of Earth. That said, the closer proximity to the Sun may have allowed a runaway greenhouse effect on Venus to create a very thick atmosphere easily able to deflect the stronger Solar Wind.

With respect to Mars; I wouldn’t be surprised if a comet scarred the Martian surface and took much of the atmosphere with it – not the solar wind. In fact the Solar wind appears to help protect the Solar system from dangerous highly energetic cosmic Rays from outside the Solar system.

https://www.nasa.gov/press-release/nasa-mission-reveals-speed-of-solar-wind-stripping-martian-atmosphere

Quote

MAVEN measurements indicate that the solar wind strips away gas at a rate of about 100 grams (equivalent to roughly 1/4 pound) every second. "Like the theft of a few coins from a cash register every day, the loss becomes significant over time," said Bruce Jakosky, MAVEN principal investigator at the University of Colorado, Boulder. "We've seen that the atmospheric erosion increases significantly during solar storms, so we think the loss rate was much higher billions of years ago when the sun was young and more active.”

 

In addition, a series of dramatic solar storms hit Mars’ atmosphere in March 2015, and MAVEN found that the loss was accelerated. The combination of greater loss rates and increased solar storms in the past suggests that loss of atmosphere to space was likely a major process in changing the Martian climate.

 

The solar wind is a stream of particles, mainly protons and electrons, flowing from the sun's atmosphere at a speed of about one million miles per hour. The magnetic field carried by the solar wind as it flows past Mars can generate an electric field, much as a turbine on Earth can be used to generate electricity. This electric field accelerates electrically charged gas atoms, called ions, in Mars’ upper atmosphere and shoots them into space.

https://www.esa.int/Science_Exploration/Space_Science/Venus_Express/Caught_in_the_wind_from_the_Sun

Quote

In particular, the interaction causes Venus’s atmosphere to lose its gases in the form of ionized particles. The Analyzer of Space Plasmas and Energetic Atoms (ASPERA) on Venus Express has been studying this interaction and has revealed, for the first time, the composition of the escaping particles. They are predominantly hydrogen, oxygen and helium ions.

Venus loses water

The first two components of the escaping ions are highly important because they are the chemical constituents of water. Water molecules are thought to be the principal contributors of hydrogen in the upper atmosphere of Venus. The solar ultraviolet radiation breaks water into electrically charged ‘atoms’, turning it into what scientists call a plasma, and this plasma is then accelerated into space. Thus, two hydrogen atoms should be escaping for every one of oxygen.

The highly elliptical polar orbit of Venus Express, with its closest approach to the planet of 250–350 km and its furthest reach of 66,000 km, is perfect for studying the escaping planetary ions. This is because it covers the region of the solar wind interaction near the planet and the region directly downstream of the planet, as well as for reference the unperturbed solar wind far away from the planet.

Prior to Venus Express, scientists knew that particles were probably escaping from Venus’s atmosphere but they could only guess the composition of those particles.

ASPERA finally established the composition of the escaping plasma and measured that the escape of hydrogen to oxygen is, indeed, in the same ratio as water: two hydrogens for every oxygen.