After greater than two and a half years of driving and exploring, Perseverance is closing in on an eagerly anticipated vacation spot: the margin carbonate unit.
The Mars 2020 scientists have been buzzing with pleasure this previous week as Perseverance makes its last strategy in the direction of a particular rock unit that performed a pivotal position in choosing Jezero because the touchdown web site for exploration. Situated in a slender band alongside the interior fringe of Jezero’s western crater rim, this layer showcases pronounced signatures of a mineral often called carbonate.
On Earth, carbonates sometimes type within the shallow shoals of freshwater or alkaline lakes. It’s hypothesized that this is perhaps the case for the margin carbonate unit on Mars too—over 3 billion years in the past, the waters of a lake in Jezero crater may need lapped towards its shores, depositing this carbonate layer. Another speculation is that the carbonates fashioned by way of mineral carbonation, the place silicate minerals (like olivine) react with CO₂ and are transformed to carbonates.
Carbonates are intriguing for a number of causes. Firstly, carbonates can provide insights into Mars’ bygone ambiance. These minerals type by way of a sequence of chemical reactions that start when carbon dioxide (CO₂) from the ambiance reacts with liquid water. Thus, by finding out the presence, abundance, and isotopic composition of those carbonates, our staff could possibly infer Mars’ previous atmospheric CO₂ ranges and glean insights into its climatic historical past.
Second, carbonate minerals are a wonderful medium for preserving traces of historic life if it existed. When carbonates precipitate early within the rock-forming course of, they’ll seize a snapshot of the setting wherein they fashioned, together with any indicators of microbial life.
On Earth, carbonate minerals have been noticed to type instantly round microbial cells, encapsulating them and quickly turning them to fossils. That is notably priceless as a result of as soon as an organism is encased in carbonate it may be preserved for a really very long time. One other instance of carbonate fossilization on Earth is stromatolites—layered buildings created by microbial colonies rising in mineral-saturated waters. Stromatolites signify a number of the earliest data of life on Earth.
Though we don’t but know precisely how the margin rocks, or the carbonate inside them fashioned, the staff is raring to drill into these rocks and unlock their secrets and techniques.
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Astrobiology
