May 29, 2020
Briony Horgan, Professor of Planetary Science at Purdue University, joins us to discuss the Mars 2020 Perseverance Rover Mission. Perseverance will launch in July 2020 (link below) and is scheduled to land on Mars at the Jezero crater in February 2021. How does NASA decide where to send the next Rover? Horgan was part of a team of scientists that evaluated Jezero crater as one of the candidate landing sites. She used satellite data to help think about the science that Perseverance could conduct at Jezero crater. Horgan explains that some of the best science you will see occurs as candidate landing sites are evaluated by scientists. Every participating scientist is invested in defending their landing site and many have very strong opinions. Perseverance follows Spirit and Opportunity, which were previous rovers searching for evidence of water on ancient Mars. The Mars Science Laboratory Curiosity Rover Mission followed up with the findings from Spirit and Opportunity by analyzing the chemistry of rocks at those ancient watery environments to determine whether that water could have supported life. Curiosity found evidence of a long-lived, habitable lake environment at Gale crater. Now that we know Mars had a habitable body of water, the Perseverance Rover Mission will be searching for signs of ancient microbial life on Mars. Jezero crater was selected because it seems to be the best example for evidence of an ancient crater lake on Mars. Horgan explains the complicated process, (Mars Sample Return), of collecting samples retrieved by the Perseverance rover and sending those samples back to Earth. Another point that Horgan makes is that NASA is concerned with planetary protection. The idea of planetary protection involves the consideration that we should avoid returning samples from another planet that could be potentially harmful to Earth. Also, contaminating other planets with Earth life should be avoided in order to reduce complications related to the understanding of the evolution of extraterrestrial life. One of the consequences of planetary protection is that NASA will not send missions to places where there may be even a slight chance that life may be living today. NASA also will not send anything nuclear powered to places where subsurface ice exists. In the event of a crash, there is concern that a nuclear powered spacecraft could melt subsurface ice and create a refuge for Earth life that would contaminate the extraterrestrial environment. A future mission idea might involve sending a rover to the Mars polar caps to collect ice core samples so that climate change on Mars can be better studied. This would help us refine our climate and atmospheric models for Earth systems.