Curiosity Rover Uncovers Clues to Mars’ Atmosphere

April 21st, 2025

Anya Gordeev

This week, NASA’s Curiosity rover has discovered evidence that could solve one of Mars’ greatest mysteries: where did its thick, life-supporting atmosphere go?

Curiosity uses an onboard X-ray diffraction tool called CheMin to analyze powdered rock samples. According to NASA researcher Thomas Bristow, drilling just a few centimeters down is like “reading a history book,” offering insight into how minerals formed 3.5 billion years ago. While exploring the Gale Crater on Mars, Curiosity identified a mineral called siderite. This mineral is a carbonate that forms in water and traps carbon dioxide. Curiosity’s recent drill samples revealed 5–10% siderite by weight, hidden beneath the surface where traditional satellite instruments likely missed it. The presence of siderite suggests Mars had an active carbon cycle, but one that concealed more CO₂ than it returned (unlike Earth’s balanced system). Earth’s carbon cycle balances CO₂ between the atmosphere and surface, but Mars’ seems to have been largely one-way. “CO₂ goes down, it doesn’t come back up,” said geochemist Benjamin Tutolo, who studies carbon sequestration on Earth. Over time, massive amounts of CO₂ were locked into rocks and thinned Mars’ atmosphere, ultimately making it uninhabitable. This pivotal scientific discovery could help explain how Mars lost its atmosphere and its habitability.

The discovery may finally explain the mysterious absence of carbonate minerals on Mars, which had perplexed scientists for decades. Planetary scientist Janice Bishop of the SETI Institute called the finding “a great explanation for where the missing carbonate is.” For scientists, some next steps may involve examining orbital data, delving into future missions to uncover more carbonate rich deposits, and possibly bringing samples back to Earth to all offer deeper insights into Mars' climate. Either way, Curiosity has brought scientists one step closer to understanding how Mars transformed from a once habitable environment with a functioning atmosphere into the dry, arid desert it has become today.

Extemp Analysis by Daphne Kalir-Starr

Does humanity truly have a future on Mars?

AGD: While there are many ways one could tackle this AGD, I think a joke is the most intuitive. I would search something up about Elon Musk and Mars (I think he is a really safe bet for a joke these days since his approval rate is so low, the risk you run here is just straining it too far.) Maybe a line like “Billionaire, and potential alien Elon Musk recently proposed a name for a Martian city: terminus. Which is ironically what's about to happen to his job, and situationship with Donald Trump.” In my opinion, an AGD doesn’t have to be laugh-out-loud-funny. A good rule of thumb (from your resident unfunny extemper,) think of something funny enough to be exhale-out-of-the-nose funny. Just enough to get your judge to chuckle, and think you made an effort. I think another interesting way one could take this AGD is by telling the story of a recent climate disaster, and segueing by saying “but while the solution to climate change may be far away, scientists are compelling us to look even further, all the way to outer space.” I think that could potentially be really cool if you wanted to make this speech advocating for anti-Mars.

Background: Limit this to three sentences. I’d probably do one about how people are worried about climate change, natural disaster, etc . . . the second about people seeing Mars as a viable option to live, and maybe the third about the recent discoveries mentioned in the article above?

SOS: This should absolutely be something about the dangers climate change poses. “So considering, that climate change scientist John Doe explains, by 2050, XYZ many people will be displaced due to disaster, yet now, EITHER we’re telling people the most viable solution isn’t to stand by our planet but escape our problems OR yet now, it seems like our salvation might be worlds away, we need to ask...”

Answer: I think the answer to this is probably no. I think one risks fighting too much judge bias if one chooses to say yes.

Anatomy of a point: My preferred substructure for this question is criteria/lack of fulfillment

Infeasible financial cost

a. For humanity to live on Mars, we’d need to commit billions of dollars

b. NASA’s funding is being CUT, but even if not, we are unwilling to commit the money

International conflict

a. For humanity to live on Mars, we’d need to cooperate internationally to create consensus over rule of law, land, ex.

b. There's no way we’d be able to come to an agreement w/ other countries and it would likely turn into a space race to see who could conquer first. In the end, impossible to settle

Absence of hospitable atmosphere

a. For humanity to live on mars, the atmosphere needs to support us

b. The atmosphere is dangerous for XYZ reason