> "The first such feature on the moon—a hole 50 meters across and dozens of meters deep—was discovered more than a decade ago in an image captured by Japan’s SE

> "The first such feature on the moon—a hole 50 meters across and dozens of meters deep—was discovered more than a decade ago in an image captured by Japan’s SELENE orbiter. Many more skylights have been found on the moon since then, and hundreds of possible skylights have been spotted on images snapped by Mars orbiters, the first of which were taken in the mid-1970s. Interesting. I didn't know that we've spotted that many likely candidates on Mars.