Initially, scientists analyzed the gas pockets within the minerals of meteorites and compared them to the known atmosphere on Mars, which was established by NASA’s Viking rovers in 1976. When the gases match perfectly, scientists could conclude the meteorites came from Mars.
Starting in the 1990s, however, scientists like me began using cheaper and easier techniques to determine martian provenance, such as oxygen isotopic compositions, which are like atomic barcodes that are unique for each planet.
All told, the 261 known meteorites from Mars collectively weigh around 440 pounds. Scientists study them using the same instruments and techniques we use to study Earth samples. My colleagues and I are interested in determining how and when these rocks were formed and how they are linked to each other.
Mysterious Mars
Unfortunately, my colleagues and I do not know where on the martian surface the meteorites come from, but many are working to figure that out. We have been able to determine the different ages of the rocks themselves. We still do not know for sure if the core of Mars is liquid or not, but the meteorites inform us about how and when volcanoes were formed on the planet.
NASA’s Perseverance rover will be exploring an area called the Jezero crater. Igneous rocks, created by volcanic activity, are likely to be present, so it will be really interesting to study the history of the crater, which formed around 4 billion years ago. The Jezero crater also contains two large deltas, where we expect to find sediments that were once transported and deposited by rivers that existed long ago.
For scientists who study martian geology, having diverse samples from a known field location will greatly boost our understanding of Mars’ core, the history of its climate and the potential life that once may have existed there.
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Arya Udry, Assistant Professor of Igneous Petrology, Planetary Science, University of Nevada, Las Vegas
This article is republished from The Conversation under a Creative Commons license. Read the original article.