How did Mars transform into an inhospitable desert?
At a Glance
NASA’s Curiosity rover landed on Mars in 2012 to search for evidence that the planet could once have supported Earth-like life. It found that its landing site, Gale Crater, once had a calm lake that could have supported life.
Curiosity is now studying how Mars' environment transformed into an inhospitable desert. Its ongoing weather and radiation observations are helping prepare for human exploration of Mars.
The White House’s latest budget proposal cuts Curiosity’s funding by 20 percent. The Planetary Society is working with Congress and NASA to reverse those cuts, and you can help.
Why do we need Curiosity?
Curiosity’s original mission was to figure out whether conditions in Mars’ past were once amenable to life as we know it. The rover’s predecessors, Spirit and Opportunity, found that water once existed on Mars’ surface. But whereas Spirit and Opportunity were leaner, robot field geologists, Curiosity was a full-blown mobile science laboratory that would use its instruments to determine whether samples it collected formed in an environment that had the right chemical mixture for life.
Millions of people watched Curiosity’s riveting landing on 5 August 2012, including thousands spontaneously gathered in New York City’s Times Square, and 3,000 Planetary Society members watching in Pasadena, California. The new and daring landing process, dubbed the “7 minutes of terror” after the amount of time it took Curiosity to travel from space to Mars’ surface, involved a supersonic parachute and rocket-powered “skycrane” that lowered the rover to the ground via nylon cables.
Watching Curiosity Land on Mars
A couple in Times Square listens intently to the news reports as NASA's Curiosity rover attempts to land on Mars.
Within a year, Curiosity achieved its primary goal of verifying that Gale Crater, where it landed, was an ancient lakebed that had water and chemical elements that once could have supported life.
Mars once had liquid water. Did it also have life? Learn why and how we study the 4th planet, and how you can get involved.
Now in extended mission operations, Curiosity is climbing the slopes of Mt. Sharp, a 5-kilometer-tall mountain in the middle of Gale Crater that preserves eons of Martian history in its rock layers. As it drives up the mountain, Curiosity is studying how Mars’ environment changed from a clement one with lakes filled with drinkable water, to one where the waters were highly acidic, to one with no surface liquid water at all.
By continuing to gather weather data as it drives uphill, Curiosity is helping Mars meteorologists understand how the planet’s atmosphere and dust levels change with increasing elevation, which will help them make better weather predictions in the future.
NASA / JPL-Caltech / MSSS / Séan Doran
Mount Sharp from Vera Rubin Ridge
Suitable for desktop wallpaper, a segment from a 360-degree panorama taken by Curiosity on sol 1903 (December 13, 2017). The hills look impassable in this direction, which is one reason Curiosity will be driving significantly toward the left (east) before descending Vera Rubin Ridge, crossing the clay-rich area behind it, and ascending the sulfur-rich lower layers of the mountain.
How Curiosity explores Mars
Curiosity is a mobile science laboratory. Using images from navigation cameras placed strategically around the rover, as well as images from orbital satellites such as NASA’s Mars Reconnaissance Orbiter—scientists and engineers work together to drive Curiosity across the floor of Gale Crater, stopping for weeks to months at a time to collect data and drill at scientifically interesting spots. As of 2020, Curiosity has driven about 22 kilometers (14 miles).
The rover’s robotic arm collects soil and rock samples with a drill and scoop, and then drops them into its belly for analysis. SAM, short for Sample Analysis at Mars, figures out what carbon-containing compounds and other materials necessary for life are preserved in the rocks. CheMin, the Chemical and Mineralogy instrument, analyzes the types of minerals present in the rocks to tell how favorable to life the environment was when the rocks were first laid down as sediments.
NASA / JPL-Caltech / MSSS
A view inside the Curiosity SAM inlet
On sol 2155, Curiosity used its Mastcam to take a look at the condition of one of the two SAM instrument inlets on the rover deck. The spring-loaded cover is open, revealing the relatively clean funnel that accepts samples dropped from the arm turret.
Curiosity takes selfies by stretching out its robotic arm and turning the MAHLI camera back on itself. Because the camera’s field of view is so narrow, multiple images must be taken and stitched together back on Earth. The robotic arm must be cropped out in the process, which can cause confusion for people viewing the stunning result.
The White House's latest budget proposal cuts NASA's Mars Exploration Program by 3%. While that seems small overall, it falls disproportionately on 3 current Mars missions, including Curiosity, which would see a 20 percent drop in operations funding that would decimate its science productivity.
In 2019, NASA’s plan for a 3-year extension to Curiosity’s mission received a grade of “excellent”—the highest possible rating—from an independent review panel, which noted its high potential science return. The savings achieved by cuts to the Mars Exploration Program would account for less than one percent of NASA’s overall planetary science budget.
The Planetary Society is working with Congress to restore these funds in order to maximize Curiosity’s scientific productivity and generate the highest possible return on investment for U.S. taxpayers. You can sign up for our monthly Space Advocate Newsletter to stay engaged in NASA’s budget process and get notified when we have ways for you to take action. You can also sign up for The Downlink, our weekly toolkit that contains news, announcements, and actions you can take to support space science and exploration.
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