Short-lived means a lot of different things in the context of the universe. Planet formation goes on for millions of years, and the effects of phenomena like solar flares might last for only hours or maybe even minutes or seconds. 

Researchers studying Mars using radars on both Mars Express and the Mars Reconnaissance Orbiter have periodically experienced weird blackouts in their data where radar returns stop returning. Since studying these weird blackouts wasn’t the goal of taking radar data, understanding what is causing this has been a back burner problem that may finally be understood. 

In research led by Mark Lester and including some of our Planetary Science Institute’s researchers, Than Putzig and Matthew Perry, it has been determined that solar energetic particles can ionize the lower atmosphere on Mars, and this partial ionization prevents healthy radar returns. Basically, an active Sun means no radar science for SHARAD and MARSIS radar scientists. While this is no big deal as the research can just be done at a different time, it is problematic because if the radar can’t get through, this means that communications with future robots and humans will also be disrupted periodically by solar activity. This is just one more problem that will need to be sorted if we want to keep humans safe on Mars.

More Information

“Energetic particles and radar blackouts at Mars,” M. Lester et al., 2021 April 19-30, EGU General Assembly 2021