This graphic highlights an ongoing process at Mars: the escaping atmosphere. Ancient Mars was a lot warmer and wetter with a much thicker atmosphere than the present day, which is cold and arid. Just as the other rocky planets, Mars too would have started out with a thicker atmosphere thanks to the delivery of volatiles from asteroids and comets, and volcanic outgassing from the planet as its rocky interior cooled down. The planet’s low gravity and lack of magnetic field likely contributed to its inability to hold on to its atmosphere over time. It is exposed to the solar wind – a continuous flow of charged particles from the Sun – that, just as on Venus, continues to strip away the atmosphere even today. Mars Express has been studying the Sun-Mars interaction for more than 15 years to understand how the atmosphere is escaping. More recently, the ExoMars Trace Gas Orbiter observed that water loss from the atmosphere is more enhanced during global dust storms.
ESA has demonstrated expertise in studying Mars from orbit, now we are looking to secure a safe landing, to rove across the surface and to drill underground to search for evidence of life. Our orbiters are already in place to provide data relay services for surface missions. The next logical step is to bring samples back to Earth, to provide access to Mars for scientists globally, and to better prepare for future human exploration of the Red Planet.
This set of infographics highlight’s ESA’s contribution to Mars exploration as we ramp up to the launch of our second ExoMars mission, and look beyond to completing a Mars Sample Return mission.