The search for life
In addition to the search for molecular remains of possible former life forms, the main goal of the Mars 2020 mission is to collect samples for transport to Earth in the early 2030s. The aim is to obtain the most promising and diverse samples possible and deposit them on the surface of Mars for later return. The analysis of samples in laboratories on Earth can provide more accurate results than can be obtained with instruments on Mars rovers. Perseverance can only take samples from a relatively shallow depth of a few centimetres. However, it is thought that traces of former life are most likely to be found at greater depths, where they may have been protected from the degrading effects of UV radiation at the surface and the cosmic radiation that penetrates deeper into the soil. These deeper traces may have remained preserved over Martian history. Finally, it is assumed that the best environmental conditions for the existence of life (habitability) prevailed about 3.7 to 3.4 billion years ago. Incidentally, life on Earth also emerged during this period.
As part of the European Space Agency (ESA) ExoMars 2022 mission, the next Mars rover – Rosalind Franklin – is scheduled to land in Oxia Planum on 10 June 2023. This rover has been designed to reach deeper into the subsurface. It will be able to collect core samples from depths of up to two metres and examine them for biosignatures directly on site using highly specialised instruments inside the rover.