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

Researchers believe they have rediscovered a mysterious star system first spotted in 2011. If true, the alien sun and its ...

Our Solar System is a carefully balanced celestial ... The planet sizes tested were 1 percent of Earth's mass, exactly Earth's mass, twice Earth's mass, five times Earth's mass, and ten times ...

Could our solar system have been temporarily exposed to an enhanced flux of cosmic-rays at some point in the ancient past?

Scientists found an intriguing world in our galaxy.

"We think this is a so-called super-Neptune world orbiting a low-mass star at a distance that would lie between the orbits of ...

NASA said the system is thought to be moving at least 1.2 million miler per hour, nearly twice as fast as our solar system.

Astronomers discovered supersonic winds on a giant gas planet located over 500 light-years from Earth. In a study released Tuesday in Astronomy & Astrophysics astronomers who have been studying ...

Gravity not only maintains the stability of these orbits but also influences phenomena like tides on Earth ... our solar system. Gravity certainly describes the motion of planetary mass bodies ...