Some objects were placed in space on purpose, symbolic gestures meant to inspire or amuse. Others were lost by accident, abandoned or forgotten during ambitious missions.

Two icy moons of Jupiter, though neighboring and of similar size, exhibit radically different internal structures. A new ...

A little-known fact to the general public is that there's more moving around Jupiter's orbit than just the giant gas planet.

Nearly 400 years ago, Galileo looked at the Pleiades star cluster through his telescope and noticed that the seven or so ...

NASA have found something new moving in our Solar System. Even thought it's not water, still a phenomenon worth of time ...

In the early 1600s, Dutch spectacle maker Jan Lippershey discovered that combining lenses could magnify distant objects.

Once a star reaches the end of its life stage and becomes a red giant, any chance for life is extinguished. This is also true for our Sun, which is expected to turn into a red giant in about five ...

Given just how big space is, the solar system seems like it shouldn't be too mysterious. But there are actually plenty of questions that took years to solve.

Recent flybys of the fiery world refute a leading theory of its inner structure—and reveal how little is understood about ...

On this date, Jan. 7, 1610, astronomer Galileo Galilei, with a homemade telescope, noticed three points of light near Jupiter. Initially believing they were distant stars, Galileo’s repeated ...

On November 5, 2002, NASA's old Galileo spacecraft was almost out of fuel. But the Jupiter mission still had some science to do. ‘On This Day in Space’ Video Series on Space.com Galileo flew ...