Earth may have a moon today because a nearby neighbor once crashed into us, a new analysis of Apollo samples and terrestrial ...

Roughly four and a half billion years ago the planet Theia slammed into Earth, destroying Theia, melting large fractions of ...

Apollo samples provide evidence: Researchers analyzed Moon rocks brought back by the Apollo missions and, for the first time, ...

Scientists traced the Moon's parent planet Theia to the inner Solar System, solving a 4.5-billion-year mystery.

This artist’s concept depicts one of the solar system’s inner planets slamming into Earth after being nudged on a collision course by a passing star. Such a world-shattering cataclysm is extremely ...

Theia, the world that helped form the Moon, came from the Solar System. Chemical clues in Earth and Moon rocks reveal this ...

New research shows that Theia, the planet that collided with Earth and formed the Moon, was a rocky world born closer to the ...

Moon’s precursor planet, Theia, disappeared billions ago, leaving scientists no direct chemical evidence to support the ...

Are planets in the solar system that are closer to the Sun older than the ones further away? – Gavriel, age 10, Paducah, Kentucky A cloud of collapsing gas created our Sun, the first thing to form in ...

Earth and Mars were formed from material that largely originated in the inner Solar System; only a few percent of the building blocks of these two planets originated beyond Jupiter’s orbit. A group of ...

Astronomers have spotted an intriguing cluster of objects in the Kuiper belt, an enormous, donut-shaped region of icy objects ...

Before the solar system had planets, the sun had rings — bands of dust and gas similar to Saturn’s rings — that likely played a role in Earth’s formation, according to a new study. “In the solar ...