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

Planets with suns like Wolf 359 are subject to huge blasts of radiation that raise questions about their long-term ...

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

Finding a world like Earth elsewhere in the universe might mean looking for the right kind of solar system. A new discovery ...

The so-called 'planetesimal belts' are filled with tiny millimeter-sized particles created by collisions between comets.

Claims of a "rare planetary alignment" are misleading; it's just visible planets. A true "golden conjunction" occurs on Sept.

To retain vast oceans similar to Earth, the planet would have to be about 10 AU away, or roughly the distance of Saturn from the sun. The second ... Generation Planets Orbiting White Dwarfs ...

Known as the "Parade of Planets," the celestial event will feature appearances from Mars, Jupiter, Uranus, Venus, Neptune and ...

You won't have to wait long for all six planets to be in the sky. They'll be there as soon as the sun sets. Once it's dark, you'll only have a couple of hours to view them before Venus ...

It actually follows its own tiny elliptical orbit around what is called the center of gravity (the barycenter) of the system, the sun and the orbiting planets. This barycenter is usually not equal ...