Tens of millions of miles beyond Earth, a nuclear-powered, car-sized rover is climbing a Martian mountain.
NASA's Curiosity rover, while investigating Mars' past, has snapped over 683,790 pictures as it's rumbled over 21 miles of unforgiving desert terrain since 2012, and a recent view shows the space agency's robot overlooking a vast Martian wilderness.
Some 3.7 billion years ago, a large object smashed into Mars, leaving the sizeable, 96-mile-wide Gale Crater we see today. When the region's surface rebounded after the powerful collision, it left a central peak, Mount Sharp, which preserves layers of the intriguing, and watery, Mars past.
From its perch in the foothills of the 3.4-mile-high mountain, you can see over an expanse of plains, called Aeolis Palus, and beyond that the hilly walls of Gale Crater. In the foreground, Martian hills are shadowed in the low sunlight.
This view, captured on March 18, 2025, was the Curiosity rover's 4,484th Martian day, or Sol, on the Red Planet. (A Martian Sol is a bit longer than a day on Earth, at 24 hours and 39 minutes.)
Today, the Martian world we see is 1,000 times drier than the driest desert on Earth. But evidence gathered by rovers and spacecraft operated by NASA and other space agencies shows this wasn't always the case. A vast Mars ocean may have blanketed a swath of the world, and lakes once fed gushing rivers and streams.
As Curiosity has scaled Mount Sharp, it has encountered rocks with minerals (sulphates) that show when Mars began to dry out. It has also revealed ripple formations on the surface, which is compelling evidence of small waves breaking on lake shores billions of years ago. Observations like this suggest that Mars once was warm, wet, and quite habitable before it gradually transformed into the extremely dry and frigid desert we see today.
"Taken together, the evidence points to Gale Crater (and Mars in general) as a place where life — if it ever arose — might have survived for some time," NASA explained.
Still today, there's no certain proof microbial life ever existed on Mars. But Curiosity's robotic sibling, the Perseverance rover, has found intriguing rock samples that could potentially show evidence of past microbial activity. (The samples must be robotically returned to Earth to inspect.)
Curiosity is currently headed to a new destination on Mount Sharp, a place home to expansive and compelling "boxworks" formations. From space, they look like spiderwebs. "It’s believed to have formed when minerals carried by Mount Sharp's last pulses of water settled into fractures in surface rock and then hardened," NASA explained. "As portions of the rock eroded away, what remained were the minerals that had cemented themselves in the fractures, leaving the weblike boxwork."
What more might the boxworks reveal? Godspeed, Curiosity.
