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NASA has just hit a milestone that is truly out of this world. Sorry about that. The Mars rover Perseverance set a new record for the longest distance traveled by an off-Earth vehicle. Here's NPR's science reporter Ari Daniel.
ARI DANIEL, BYLINE: Perseverance is a lot of things to Katie Stack Morgan, the project scientist for the rover. Above all, she finds the robot inspirational.
KATIE STACK MORGAN: I think of Perseverance as an intrepid explorer.
DANIEL: When it touched down on Mars a bit more than 5 1/2 years ago, the rover began its mission in the Jezero Crater, where researchers believe there may have once been an ancient lake.
STACK MORGAN: Our exploration culminated in our discovery of a potential biosignature in some rocks within the river valley that fed the crater.
DANIEL: That is, they may have found possible evidence of life, a collection of minerals whose formation, at least on Earth, would have involved microorganisms.
STACK MORGAN: And so the question is, did Martian microbes drive these reactions?
DANIEL: After that, Perseverance was sent to the rim of the crater to look at some very old rocks...
STACK MORGAN: That really represent probably about the first half billion years of solar system history.
DANIEL: All this science required the over to rove, which was enabled by a self-driving capacity that allowed it to plan its own best course to get to a destination over and over again. And now it's notched its 28th mile on the Martian surface.
STACK MORGAN: There's very specific windows when it can drive, and it's moving pretty slowly. But still, for a Mars rover, 28 miles is a really big deal.
DANIEL: And it's a new record for total drive distance on another world.
STACK MORGAN: This is the culmination of really decades of technological advancement in how we explore the solar system and the capabilities that we bring to other planets.
DANIEL: A big part of Perseverance's purpose was to collect material from the Martian surface so that, one day, another mission might return those samples to Earth.
STACK MORGAN: I certainly want those samples back, and I want them back as soon as possible.
DANIEL: But this part of the program has an uncertain future. Its hefty price tag put it in the crosshairs of the federal government earlier this year. It makes Philip Christensen, a planetary geologist at Arizona State University, furious.
PHILIP CHRISTENSEN: Here we were poised, ready to do probably the most important bit of science we could do at Mars, and it's just come to a grinding halt. So it's extremely frustrating.
DANIEL: But Christensen says he's an optimist, and he's hopeful the samples will one day make their way to Earth. In the meantime, he says that what Perseverance has been able to achieve in the last half decade is nothing short of miraculous.
CHRISTENSEN: It really is the epitome of exploration. You never know what's going to be over the next hill, around the next corner. Going those 28 miles, every foot of that terrain has been a discovery.
DANIEL: A stunning string of accomplishments for the longest off-world road trip. For NPR News, I'm Ari Daniel.
(SOUNDBITE OF MELANIE MARTINEZ SONG, "VOID") Transcript provided by NPR, Copyright NPR.
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