In our last show, we talked about some of the latest science results from NASA’s Curiosity rover, which included a bit of a look back at the past ten years on Mars. Then yesterday, NASA held a press conference to update the public on the Perseverance rover.

Perseverance landed in Jezero Crater on Mars back in 2020, which may feel both like not that long ago and also ages ago at this point. Jezero crater was once a lake back when Mars still had water, and within the crater is a river delta that formed from a river draining into that lake about 3.5 billion years ago. Project scientist Ken Farley explains the choice of landing zone: The delta, with its diverse sedimentary rocks, contrasts beautifully with the igneous rocks – formed from crystallization of magma – discovered on the crater floor. This juxtaposition provides us with a rich understanding of the geologic history after the crater formed and a diverse sample suite. For example, we found a sandstone that carries grains and rock fragments created far from Jezero Crater – and a mudstone that includes intriguing organic compounds.

And as a part of the rover’s mission, Percy is taking samples of rocks for both onboard analysis and later pickup by the planned Mars Sample Return mission. So far, a dozen samples have been taken to date. While collecting samples from a region nicknamed “Wildcat Ridge”, the rover abraded some of the rock that was then analyzed by the SHERLOC instrument. Using Raman spectrometry analysis, SHERLOC found an abundance of organic molecules. Farley notes: The fact the organic matter was found in such a sedimentary rock – known for preserving fossils of ancient life here on Earth – is important.

Organic molecules do not necessarily indicate past life; they are simply molecules that contain carbon. Understanding just what these molecules are and what they indicate about the sand, mud, and salt of the rocks on the ridge will have to wait for the sample return.

More Information

NASA press release