The number of planets that orbit the sun depends on what you mean by “planet,” and that’s not so easy to define ...

Stargazers will be treated to a rare seven-planet alignment in February. This is what scientists hope to learn.

The cosmic superstructure Quipu is more than 13,000 times the length of the Milky Way, and its mass is 200 quadrillion times ...

Worlds with liquid water could have formed just 200 million years after the big bang from the remains of the earliest ...

Researchers say they've discovered the largest known object in the universe, a galactic superstructure called Quipu.

The building blocks of life could have been delivered to Ceres by one or more space rocks from the outer asteroid belt.

A planet-size object that possibly once visited the solar system may have permanently changed our cosmic neighborhood by warping the orbits of the four outer planets, a new study suggests.

Researchers studying decades of earthquake data say they have found the first evidence that, in addition to spinning backward ...

Using the gravitational pull of a well-placed planet, such as Jupiter, to slingshot a spacecraft outwards can reduce the travel time dramatically Reaching the outer planets with a spacecraft is ...