Mars today is a completely dry, dusty planet. There’s very little water on its surface, that too in the frozen form near the poles; it has an atmosphere less than 1% as dense as Earth’s and has no life that we know of. But scientists believe that Mars once had an atmosphere thick enough to support liquid water. If we go back in time a couple of billion years, we might find lakes and oceans on Mars that supported life!
Over time the Sun slowly stripped off the Red Planet’s atmosphere to space. Lots of ions of oxygen, nitrogen, carbon and argon escaped the planet’s atmosphere; and while most of it was lost to space, some of these ions could have landed on one of the two Martian Moons Phobos, says a new study.
Phobos orbits extremely close to Mars, about 60 times closer than the Moon orbits Earth, and is tidally locked to Mars just like our Moon is locked to Earth. So only one side of Phobos always faces Mars.
According to new research Phobos orbits through a stream of charged ions and molecules that flows off the atmosphere of Mars. Scientists predict that some of these charged particles might have landed on the surface of Phobos and could be preserved on its uppermost layer. This means that if we analysed soil samples from the surface of Phobos, it could tell us about the past atmosphere of Mars and reveal information about its evolution over the years.
To reach this conclusion scientists analysed data obtained from NASA’s spacecraft Mars Atmosphere and Volatile EvolutioN (MAVEN). The spacecraft has been orbiting Mars since 2014 and gathering data for scientists to help figure out how Mars lost its atmosphere and details about evolution of the Martian atmosphere.