Earth and the Moon form a closely linked planetary system with a long shared history. Learn how their gravity, orbits, eclipses, tidal interactions, and evolving relationship influence phenomena observed from Earth.
When lunar samples were first examined in laboratories, they overturned the idea that the Moon was merely a wandering object captured by Earth. The rocks looked alien in many physical details, yet some of their deepest chemical fingerprints closely matched terrestrial material. That resemblance...
The oldest lunar highlands are the visible remains of a planetary-scale sorting process. Soon after the Moon formed, much of its rocky exterior was molten. Cooling did not simply freeze that material in place. Crystals appeared in a sequence, some sinking into the interior and others rising toward...
The Moon did not simply appear beside a finished Earth. It formed while the inner solar system was still crowded with growing worlds, when collisions between planetary bodies were a normal part of assembly. The leading explanation begins with one of those collisions: a young Earth was struck by...