NASA's Curiosity rover has been on Mars for 7 years

NASA's Curiosity rover just completed its seventh year on Mars, during which the car-sized spacecraft has changed the way we understand the Red Planet.

Why it matters: Curiosity is responsible for revealing that Mars was once a wet, relatively warm and habitable world far more like Earth than scientists expected. Researchers hope that the rover will aid in even more discoveries before its life on Mars is finished.

By the numbers: Mission controllers experienced "7 minutes of terror" during its 2012 landing when a complex series of maneuvers brought Curiosity to the surface.

• Since then, Curiosity has traveled about 13 miles on Mars, according to NASA.
• The rover has drilled 22 samples of Martian dirt, chemically analyzing it to figure out what Mars may have looked like in the past.
• Curiosity is now studying Mount Sharp — an 18,000-foot mountain that has deposits dating back to the time when Curiosity's part of Mars was covered in lakes and rivers.
• NASA expects the rover can keep trucking on Mars for about 5 to 7 more years.

What's next: Curiosity discovered that Mars was likely habitable for millions of years. The rover will use its remaining years to try to solve the mystery of why that habitability ended.

• "Did the climate change dramatically? The answer may be recorded in the rocks ahead," Curiosity project scientist Ashwin Vasavada told Axios via email.
• Vasavada also said that the rover will be on the lookout for methane — a gas that, on Earth, can indicate life — to try to figure out where the intermittent bursts of methane on the red planet are coming from.