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NASA/JPL/Caltech

Mission to Mars!

A new rover heads to the Red Planet to search for signs of alien life

By Alessandra Potenza
From the February 2021 Issue
Other Focus Areas: Technology
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As you read, think about what questions you would investigate if you were planning a mission to Mars.

The Perserverence Rover on the surface of Mars

NASA/JPL/Caltech

  • Perseverance has 23 cameras, more than any other rover sent to Mars.
  • The rover’s arm can extend 7 feet. It has a drill to collect small samples of Martian rock.
  • Rocks are sealed in tubes and stored in the rover. Later, the tubes will be dropped on the ground to be picked up by a future mission!

Does life exist outside of Earth? Humans have been asking this question for centuries. We might soon have an answer—thanks to a new rover expected to land on Mars this month!

The car-sized vehicle is called Perseverance. It’s the fifth rover the U.S. space agency NASA has sent to the Red Planet since 1997. Perseverance contains high-tech instruments to collect rocks and soil and look for signs of past life. 

NASA plans to eventually fly those samples to Earth to study. The research could reveal whether living organisms have ever existed on Mars—and whether they’re still there today. “We’ll have the opportunity to answer questions that we’ve been asking for a long time,” says Ken Farley, a lead scientist with the mission.

Barren Land

Conditions on Mars are far more extreme than those on Earth. The average temperature is a bone-chilling -63°C (-81°F). The atmosphere contains mostly carbon dioxide gas, making the air unbreathable for humans. There’s no water on the planet’s surface. Mars also receives large amounts of radiation from the sun. This powerful energy can damage living and nonliving things. “If you could put food on Mars, it would be baked beyond recognition,” says Tanja Bosak. She’s a scientist at the Massachusetts Institute of Technology who’s part of the mission. 

But evidence suggests that 3.5 billion years ago, the planet was much different. For one, it was warmer. Rivers snaked along the surface and poured into lakes. Rain probably fell from the sky. Scientists think that tiny organisms called microbes could have thrived in these conditions. To find out, the Perseverance rover will explore an area that was once a lake called Jezero Crater (see Exploring Mars). 

On Earth, microbes form a slimy layer at the bottom of lakes. They clump together with sediments and eventually die. Over time, the microbes and sediments form large rocky structures. Perseverance will use cameras to look for similar structures on Mars. It will use other instruments to determine what the rocks are made of. 

Back on Earth, Bosak and other scientists will analyze Perseverance’s photos and monitor what the rover finds. If they think a rock looks promising, they will direct the rover to investigate it.

Precious Rocks

A rocket surrounded by a plume of smoke as it launches

United Launch Alliance

The rover launched into space from Florida in July 2020. It took seven months to reach Mars.

Perseverance can analyze rocks in many ways. One instrument can search rocks for organic compounds. These substances make up living organisms on Earth. Another instrument will search for patterns in the rock that look like cells from microbes. These pieces of evidence would suggest that organisms once lived in the ancient lake. But in order to be sure, scientists need to analyze the rocks in labs on Earth. “To really look for life, you need a lot of different lab equipment,” Bosak says.

That’s why Perseverance also contains a drill. The rover will use the drill to collect at least 20 rock samples the size of a piece of chalk. It will seal the samples inside tubes and store them in its belly.

Perseverance isn’t designed to return to Earth. Scientists plan to send another spacecraft to Mars to pick up the rover’s samples and fly them home. But that will take time. “The earliest the samples could come back is 2031,” says Farley.

Understanding Mars

Even if Perseverance can’t detect signs of ancient life, its findings could help answer other important questions about Mars. For example, when exactly did a lake exist in Jezero Crater? And why did it disappear?

During its mission, the rover will also perform tests and measurements to pave the way for future human trips to the Red Planet. One instrument will try to turn carbon dioxide in the atmosphere into oxygen that humans could breathe. Perseverance will also analyze Martian dust to see if it would be harmful to people.

Finally, the rover will launch a softball-sized helicopter to test if it can fly through the air, which is much thinner than Earth’s. That experiment will help scientists build drones that could fly across Mars to explore.

It could take until April for Perseverance to begin collecting data. First, NASA has to make sure all the instruments work. Scientists like Bosak are excited about what the rover will reveal about life on Mars—and Earth. “By looking at Mars, we end up learning so much about our own planet and how unique it is,” she says.

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