The universe is supposed to look the same no matter where you stand. That idea, known as the cosmological principle, sits at the heart of modern astrophysics. It says matter spreads out evenly when ...

Astronomers have found new evidence that a mysterious ninth planet may be hiding at the edge of the solar system - rewriting what we know about the cosmos again. An international team from Taiwan, ...

A newly discovered object speeding through our solar system is sparking excitement among astronomers because it’s not from around here. Believed to be a comet, the object is only the third celestial ...

Nothing manmade has reached further from Earth than the Voyager series of spacecraft. Hurtling away from the sun at 38,000 miles an hour, the duo have now traveled over 12 billion miles, with Voyager ...

A NASA mission to study the heliosphere—the sun's magnetic bubble that shields our solar system—and develop a better understanding of space weather was launched from the agency's Kennedy Space Center ...

A new analysis estimates that the asteroid belt is steadily losing mass each year, and may not be as permanent a feature of the solar system as we thought. When you purchase through links on our site, ...

WASHINGTON, July 3 (Reuters) - Astronomers are tracking a newly spotted comet hailing from parts unknown, only the third time such an interstellar object has been observed visiting our solar system.

The Oort Cloud, an expanse of icy bodies in the far reaches of our solar system, is shown here in a scene from "Encounters in the Milky Way," a show at New York City's Hayden Planetarium that spawned ...

How fast and in which direction is our solar system moving through the universe? This seemingly simple question is one of the key tests of our cosmological understanding. A research team led by ...