A Rover Retrospective: Turning Trials to Triumphs in 2024

Perseverance’s past year operating on the surface of Mars was filled with some of the mission’s highest highs, but also some of its greatest challenges. True to its name and its reputation as a mission that overcomes challenges, Perseverance and its team of scientists and engineers turned trials to triumphs in yet another outstanding year for the mission. There’s a lot to celebrate about Perseverance’s past year on Mars, but here are three of my top mission moments this year, in the order in which they happened. 

In early January the SHERLOC instrument’s cover mechanism stopped responding during a routine attempt to acquire data on a rock outcrop in the Margin unit. After six weeks of team diagnostics, the SHERLOC instrument was declared offline and many of us feared that the instrument had met its end. In early March, the team made significant progress in driving the cover to a more open position. Then, to everyone’s surprise, the SHERLOC cover moved unexpectedly to a nearly completely open position during a movement of the arm on sol 1077. I remember staring in wonder at the image of the cover (taken on sol 1079), feeling real optimism for the first time that SHERLOC could be recovered. The team spent the next few months developing a new plan for operating SHERLOC with its cover open, and the instrument was declared back online at the end of June.  

No top list would be complete without Perseverance’s discovery in July 2024 of a potential biosignature in the form of sub-millimeter-scale “leopard spots” at an outcrop called Cheyava Falls. These features, which formed during chemical reactions within the rock, have dark rims and light cores and occur together with organic carbon. On Earth, these chemical reactions are often driven by or associated with microbes. Although we can’t say for sure that microbes were involved in the formation of the leopard spots at Cheyava Falls, this question can be answered when Perseverance’s samples are returned to Earth. In the meantime, this rock remains one of the most compelling rocks discovered on Mars.  

Closing out 2024 on a high note, in mid-December Perseverance arrived at the top of a sequence of rock exposed on the western edge of the Jezero crater rim called Witch Hazel Hill. These rocks pre-date the formation of Jezero crater and could be amongst the oldest rocks exposed on the surface of Mars. These rocks have the potential to tell us about a period of solar system history not well-preserved on our own planet Earth, and they may record important clues about the early history and habitability of Mars. Witch Hazel Hill first caught my attention during landing site selection several years ago, when we were debating the merits of landing Perseverance in Jezero versus sites outside the crater. At the time, this area seemed just out of reach for a Jezero-focused mission, so I’m thrilled that the rover is now exploring this site!   

The Mars 2020 mission had its ups and downs and a fair share of surprises during 2024, but we are looking ahead to 2025 with excitement, as Perseverance continues to explore and sample the Jezero crater rim.

Written by Katie Stack Morgan, Mars 2020 Deputy Project Scientist