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

The formation of our solar system from a singular nebula raises an intriguing question: why did each planet develop with a ...

While the composition of gas and dust in a molecular cloud is fairly uniform, everything changes once a star begins to form.

It is not just within our Solar System that planet alignments are useful. Astronomers use alignments to probe many different ...

Mars, Venus, Jupiter and Saturn should be visible to the naked eye, but get a telescope and you can spot Neptune and Uranus.

A very rare treat is about to grace Earth's night skies.

Six planets are parading across the sky, appearing as some of the night's brightest stars. A few easy tips can help you ...

Astronomers have discovered extremely powerful winds pummeling the equator of WASP-127b, a giant exoplanet. Reaching speeds ...

A U.S. scientist searching for a civilization across 7 Earth clones circling the red dwarf star TRAPPIST-1 says its own alien ...

Plate tectonics give Earth its mountains, earthquakes, continental drift and maybe even helped give rise to life itself. But do other planets in the solar system have them too?

Worlds will align for a "planetary parade" in January, with four bright and easily visible to the naked eye. But an even ...