An artist's impression of the collision between the early Earth and Theia, which may have formed the moon MPS / Mark A. Garlick Around 4.5 billion years ago, a planet called Theia is thought to have ...

The moon's orbit isn't a perfect circle. Instead, it's more stretched out, kind of like an oval, which means its distance from Earth varies by about 30,000 miles (48,000 km). The surface of the moon ...

This means that the lunar regolith could still hold a very long-term record of Earth's atmospheric history, which in turn ...

Apollo samples provide evidence: Researchers analyzed Moon rocks brought back by the Apollo missions and, for the first time, used their iron isotope ratios to trace where Theia originally formed.

When you look up in the night sky, our moon is unmissable.Just like Earth, it's round and has a solid, rocky surface. But is our moon actually a planet? The answer is technically no — at least ...

Forbes contributors publish independent expert analyses and insights. An award-winning reporter writing about stargazing and the night sky. A “planet parade” is happening in the pre-dawn sky at the ...

This month’s stargazing agenda brims with planet sightings. We have planet pairings, moon-planet hangouts, and a special treat to end the month: several evenings with all seven of our space neighbors ...

Forbes contributors publish independent expert analyses and insights. An award-winning reporter writing about stargazing and the night sky. Each Monday, I pick out North America’s celestial highlights ...