NASA today explains on its site that the robot MESSENGER spacecraft now orbiting Mercury (the iron planet, for reasons still unknown) has discovered unusual hollows on that first rock from the sun. According to NASA, “The rounded depressions appear different than impact craters and nothing like them has been noted on Earth’s Moon or anywhere else in the Solar System.”
Image Credit: NASA/JHL APL/CIW
The image above NASA says, is a shot taken of a section of the floor of Raditladi impact basin. It’s about 40 kilometers wide and includes the mountains of the central peak. “One progenitor hypothesis is that the hollows formed from the sublimation of material exposed and heated during the violent impact that created the Raditladi basin,” reps say. It is NASA’s image of the day today.
So what are they? NASA says “the slightly bluish tinge of features dubbed hollows has been exaggerated on the above image by the robotic MESSENGER spacecraft currently orbiting Mercury.” NASA’s MESSENGER robotic craft, by the way, is Earth’s first ever spacecraft to orbit Mercury. It will explore that mysterious planet — made of iron and with no moons — next year.