Martian mudstones contain features that NASA says are the "clearest sign of life" yet on Mars, according to new findings from NASA’s Perseverance rover released Sept. 10.

We'll likely need to get Perseverance's samples to Earth to determine if they do indeed harbor evidence of Mars life —but the prospects of such a mission are cloudy at best.

As NASA's Perseverance rover, a car-sized robotic explorer, looks for signs of possible ancient life on Mars, it has stumbled across some interesting things. Recently, on Aug. 31 (the 1,610th sol, or Martian day, of its mission), Perseverance captured an image of this rock, which looks like the head of a turtle coming out of its shell.

Prize: NASA could offer a prize—say $3 billion to the first company and $1 billion to a second company—for delivering something like 1 kg of Mars rocks and soil back to Earth. NASA has used prizes very sparingly in the past, but this option could appeal to the Trump administration as it would require very little funding up front.

NASA's Perseverance rover has added to its trove of curious finds, as the space agency published a photo of a rock on the surface of Mars that looks like a centuries-old helmet. The rock has a pointed peak, a flared "brim," and textures that could lead reasonable observers to compare it to a witch's hat or a tent.