There are mysterious channels on Mars They look like canyons in Antarctica caused by melting glaciers, but the elevated locations of many of the features are not places where we would expect to find flowing water, RT reported.
How did these Martian canyons form? Sublimation of carbon dioxide ice has been put forward as an alternative hypothesis, but a new study by a team of scientists in the US suggests that in the right conditions, liquid water could really do the trick. Moreover, this would have happened very recently with respect to geologic time scales, perhaps only 630,000 years ago.
The key is the tilt of the planet’s axis. When this tilt reaches 35 degrees, new simulations of temperature and circulation show that the density of the atmosphere will cause the surface temperature to rise above freezing point for a brief period. It would be sufficient to melt some of the snow and ice that remains on Mars.
“We know from a lot of our research and that of others that, early in the history of Mars, there was running water on the surface with networks of valleys and lakes,” says Brown University planetary scientist Jim Head. “But about 3 billion years ago, all that liquid water was lost.” And Mars has become what we call an extremely dry desert or a polar desert.”
Calculations by the research team shed more light on how these canyons begin to form, how much erosion they cause, and how far they can extend. The team was able to fit their model with data from the Terra Sirenum region of Mars, and match it to periods when it was thought that canyons expanded rapidly in the region.
A double-groove scenario is where channels created by melting snow are eroded by the evaporation of carbon dioxide frost. It is likely that these sites still contain reserves of ice trapped below the surface, and there could be much more of them than in the past.
The erosion of flowing water fits better with the features of the Martian landscape than erosion associated with carbon dioxide, which has no equivalent on Earth that we can study, and does not tend to cause the same effects on the rocks it comes into contact with. This type of activity has been observed on Mars in modern times, through high-resolution satellite images.
“Our study shows that the global distribution of the grooves can be best explained by liquid water over the past million years. Water explains the elevated distribution of the grooves in ways that carbon dioxide cannot. This means that Mars It was able to produce liquid water in sufficient quantities to erode the canals over the past million years, which is very recent on the scale of Mars’ geological history.”
The tilt of Mars’ axis is known to change over time, although it takes hundreds of thousands of years. This movement has previously been linked to ice ages on the Red Planet.
Just as the operation of melt water on Mars in the relatively recent past would have made it easier for organisms to evolve, so the research offers an interesting new perspective on the potential for life on Mars as well.
Eventually, the planet will return to a 35-degree angle, allowing localized splashes of liquid water to flow back in.
To bring water back into the dry valleys of Antarctica, life stagnates when liquid water is not available. It is not inconceivable that something similar could happen on Mars as well.
