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?

NASA announced Wednesday that the odds of the up to 300-foot-wide asteroid hitting Earth dropped from record highs. See where ...

Astronomers may have discovered a scrawny star bolting through the middle of our galaxy with a planet in tow. If confirmed, ...

Jess Thomson is a Newsweek Science Reporter based in London UK. Her focus is reporting on science, technology and healthcare. She has covered weird animal behavior, space news and the impacts 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.

Gaining insight could help understand the timing and process of life's emergence. A research team led by a Rutgers-New ...