Scientists identified the best place for life to have existed on Mars
So far every efforts by scientists to look for life on Mars have gone unsuccessful. With dust storms roaming and only water as permanent ice, Martian surface looks completely inhospitable as of now.
Currently due to Red planet’s atmospheric pressure (which is less than one percent of Earth’s atmospheric pressure) liquid water can not exist on its surface, except at lowest elevations for very short period.
Still, the continuous research insights by scientists show that liquid water once flowed on Red planet’s surface. Meaning Mars could have supported some sort of life form as we know it.
But the thing is how is that even possible? When our Sun was young, cool and faint in the early days of our planetary system, then how did the Mars get warm enough for liquid water.
Now a new research seems to have answer these questions. As per scientists, geothermal heat from deep inside the red planet could have risen, making the deep depths best for life to thrive.
According to planetary scientist Lujendra Ojha from Rutgers University- the computer simulations show that even if greenhouse gases (such as carbon dioxide) and water vapour are injected into early Mars’ atmosphere still climate models don’t support the long term wet and warm red planet.
Study scientists propose that if Red planet had high geothermal heat in past, then faint young Sun paradox can be adapted, at least partly.
The faint young Sun problem demonstrates the contradiction between the existence of liquid water in the early history of Solar System and the apparent faintness of the Sun.
According to astrophysicists at that time our Sun’s output would have been only seventy percent of its today’s output.
At about 227.9 million kilometers from Sun (which is 1.5 times Earth’s distance from our Sun), Mars only receives forty three percent of the solar output that Earth does, and it’s a cold place.
The average temperature of Mars is -63 degrees Celsius which is much less than our planet. However, the temperature does go above the melting point of water to some thirty degrees Celsius, but due to planet’s low atmospheric pressure ice just sublimates rather than melting.
Between 4.1 and 3.7 billion years ago at the time of Noachian period, planets’ surface is expected to had huge amount of liquid water, yet today’s climate models can’t reach the temperatures above -0.15 degrees Celsius.
The idea of geothermal heating maintaining liquid groundwater is not new. Noachian era clays and excavation of hydrothermal material from deep underground from cometary clashes support the internal heating models.
On Earth, the effects of geothermal heating can be seen below the ice sheets at high latitudes. The radioactive decay of elements (like Uranium, potassium, thorium) in the Earth’s crust generates heat which circulates through the surface.
That’s not much, however if the presence of a thick ice sheet prevents the heat from escaping, sufficient heat can be captured to melt at least some of that ice, thus creating subglacial lakes.
Scientists studied the possibility of this occurring on Mars during Noachian era. They investigated and estimated about how much heat would be needed to produce liquid water and subglacial lakes on cold and frozen planet Mars.
Further, they compared the results with other Mars datasets to establish if this would have been practical on Red planet four billion years ago.
They found that conditions to melt subsurface water would have been prevailing at that time on Mars. With volcanic activities and meteorite impacts possibly releasing additional heat.
It is possible that Martian surface was wet and warm for a time but the climate wouldn’t have been stable for long. Sometime around in Noachian era planet lost its magnetic field.
And after the loss of magnetic field, planet’s thick atmosphere (like Earth) couldn’t have stayed for long.
Liquid water (kept liquid due to geothermal heating) could only have been stable at deep depths, and (if) potential life form on Martian surface at that time could have followed the water deep below the surface.