The International Astronomical Union (IAU) defines a planet as a celestial body orbiting the Sun, possessing sufficient mass for a nearly spherical shape, and having cleared its orbital neighborhood ...

Astronomers have discovered a rare in-sync solar system with six planets moving like a grand cosmic orchestra, untouched by outside forces since their birth billions of years ago. The find, announced ...

Astronomers have discovered a rare solar system with six planets moving in sync with one another. Estimated to be billions of years old, the formation 100 light-years away may help unravel some ...

A tiny meteorite is rewriting what scientists thought they knew about the origins of our solar system. New evidence found in shavings from a meteorite known as Northwest Africa 12264 — a 50-gram (1.8 ...

CAPE CANAVERAL, Fla. — Astronomers have discovered the earliest seeds of rocky planets forming in the gas around a baby sun-like star, providing a precious peek into the dawn of our own solar system.

A new study suggests yet another theory for a possible extra planet in our solar system, likely of a size between Mercury and ...

Aliza Chasan is a Digital Content Producer for "60 Minutes" and CBSNews.com. She has previously written for outlets including PIX11 News, The New York Daily News, Inside Edition and DNAinfo. Aliza ...

This is the third time an object from outside the solar system has been found. An "interstellar object" is speeding toward the inner solar system, where Earth is located, astronomers have confirmed.

An interstellar tourist is taking a quick trip through our solar system, becoming one of just three known objects to ever do so, according to NASA. A comet from a solar system outside our own was ...