Scientists say, Mars is doomed to not have life. The reason is simple -- from the size of the planet. In theory, the radius of Mars is only half of the radius of Earth.
From the research that has been published in PNAS, this presents interesting facts that may have never been thought about why Mars cannot be a shelter for living things, as quoted from Science Alert.
"The fate of Mars was predetermined from the start," said planetary scientist Kun Wang of the University of Washington at St. Louis.
"There may be a threshold on the size requirements of a rocky planet to hold enough water to allow for habitability and plate tectonics, with a mass exceeding that of Mars. The size of an exoplanet is one of the easiest parameters to determine," Wang continued.
We can measure the size and mass of exoplanets, based on how much starlight they block as they move between us and the star. It could also be how much the star moves in its reciprocal orbit with the exoplanet. Both of these could help scientists weed out exoplanets that are too small to have a liquid water source.
There are many differences between Earth and the other terrestrial planets in the Solar System, so it can be difficult to determine which factors were conducive to the emergence of life, and which factors hindered it.
One thing that life on Earth needs is liquid water, so the conditions that allow liquid water to exist are one of the main items on the planet's habitability checklist. Mars used to have a water surface but now it is dusty, dry and desolate, and any water on its surface is frozen.
