Just the third-ever confirmed interstellar object has been detected in our solar system. Here's what we know. (Spoiler: It's not aliens.) ...

Pea-size minerals inside a meteorite are the oldest known material in the solar system, a new study says. At 4,568.2 million years old, the minerals push back the birth of the solar system by as ...

A NASA spacecraft has uncovered the solar system's "nose," which points in the direction our sun is moving through the Milky Way galaxy, astronomers say.. The finding is based on newly released ...

The Gliese system is one of several newfound solar systems, including GJ676A (not pictured). Illustration by Dana Berry, National Geographic Solar System's "Grotesque" Twin Found ...

Learn more about the solar system in the National Geographic Society’s education collection. SUBSCRIBER EXCLUSIVE This newsletter has been curated and edited by Monica Williams and David Beard ...

Once considered the ninth planet in our system, the dwarf planet Pluto, for example, is one of the largest Kuiper belt objects, at about 1,400 miles (2,300 kilometers) wide.

A ninth large planet may lurk deep in the outer solar system. The planet, illustrated here, is far from the sun and thought to be gaseous like Uranus and Neptune, though smaller than both ice giants.

Mercury is getting smaller. Over its roughly 4.5 billion years of existence, the dense little planet’s diameter could have shrunk by as much as 14 kilometers, a study published today in Nature ...

“Lucy will explore a region in our solar system never explored before,” Adriana Ocampo, the Lucy program executive at NASA headquarters in Washington, D.C., said in an October 14 press briefing.

About 300 light-years away, a giant planet has been evicted from its starry neighborhood. The world is now about 650 times farther from its star than Earth is from the sun, scientists announced ...

This story appears in the July 2015 issue of National Geographic magazine. Small, cold, and absurdly far away, Pluto has always been selfish with its secrets. Since its discovery in 1930, the ...