A major mystery that has baffled astronomers for years has finally been solved.
The so-called "man in the moon," the craters on the near side moon that, when viewed the right way, seem to resemble a yawning face, wasn't caused by asteroid strikes. A NASA initiative that's been tracking the moon's surface has helped scientists figured out that the "face" came from a volcanic eruption.
Gravitational data obtained from two NASA GRAIL spacecraft in orbit around the moon since 2012 helped scientists examine the moon's surface. The area, which is technically called the Oceanus Procellarum, spans roughly 1,800 miles.
The research: According to new research published in the science journal Nature, the basin's shapes served as a clue that it was massive plumes of lava and not asteroids.
Discovery News writes that the data from GRAIL used to examine the basin "is actually of a polygonal shape, rather than a smooth circle (or oval) that is commonly associated with impact craters. Its edges are composed of straight edges linked at 120 degree angles."
The angular outlines were produced from tension cracks in the moon's crust as it cooled around the welling up of hot lava from the interior. Mara Zuber, MIT's vice president for research, concludes that "as cracks occurred, they formed a 'plumbing system' in the moon's crust through which magma could meander to the surface."
"Magma eventually filled the region's smaller basins, creating what we see today as dark spots on the near side of the moon — features that have inspired the popular notion of a 'man in the moon,'" said MIT's report.
At least it wasn't a selfie.