Jezero crater on Mars is the landing site for the NASA Mars 2020 Perseverance rover, which is due to launch this July. It was selected as the landing site for the next Mars mission because features on its surface, such as large delta fans, indicate that it once contained rivers and lakes, making it a prime target for searching for signs of ancient life. Jezero crater is also one of the few places on Mars where carbonate minerals, associated with an ancient river-lake environment, have been detected from orbit. Previous studies hypothesized that the carbonates in Jezero crater were transported and deposited into the crater by the ancient rivers. However, a recent study by Briony Horgan at the University of Purdue and her team revealed that some of the carbonates within Jezero crater likely formed within its ancient lake. Horgan and her team conducted a detailed mineralogical and morphological study of the carbonate units within Jezero crater using high-resolution imagery and data from the Compact Reconnaissance Imaging Spectrometer for Mars (CRISM) instrument onboard the Mars Reconnaissance Orbiter. They identified a distinct carbonate-bearing unit, named the “Marginal Carbonates,” located on the inner margin of the crater close to the Western delta. The location and properties of the Marginal Carbonate unit in the crater suggest that it formed in a near-shore lake environment with neutral to alkaline waters, making it an ideal place to look for ancient biosignatures. READ MORE