Add Yahoo as a preferred source to see more of our stories on Google. The European Space Agency's ExoMars Trace Gas Orbiter image of interstellar comet 3I/ATLAS as it passed close to Mars. (The ...

The four rocky worlds closest to the sun share a common ancestry but have followed radically different paths. Mercury is still shrinking as its interior cools. Venus traps so much heat that its ...

Mercury, Venus, and Mars sit within the same general neighborhood as Earth, yet each has followed a radically different path. One kept a magnetic field against the odds. Another trapped so much heat ...

Learn more about the bizarre geological features found throughout our Solar System.

A mysterious interstellar comet — just the third such object ever confirmed to have entered our solar system — streaked past Mars last week. Subscribe to read this story ad-free Get unlimited access ...