As far-fetched as it may seem, quirks of orbital mechanics could allow hundreds of planets to be packed around a star ...

The International Astronomical Union defines a planet as a celestial body that orbits the sun, is massive enough that gravity has forced it into a spherical shape, and has cleared away other objects ...

World News China's Great Green Wall could cover 88 million acres, but scientists warn it may not be enough Since we were little, we have been taught a fairly simple image of the Solar System: the Sun ...

In the cold, dark outskirts of planetary systems far beyond the reach of the known planets, mysterious gas giants and planetary masses silently orbit their stars—sometimes thousands of astronomical ...

A sunlike star next door called Alpha Centauri A may host a huge planet, researchers report in two studies in press in Astrophysical Journal Letters. The planet candidate orbits in its star’s ...

In the process of thinking about "Why can sci-fi movies head to their destination stars without hesitation?", I realized that ...

The discovery of an Earth-like planet 4,000 light years away in the Milky Way galaxy provides a preview of one possible fate for our planet billions of years in the future, when the sun has turned ...

A stock illustration of a theoretical distant planet. In the cold, dark outskirts of planetary systems far beyond the reach of the known planets, mysterious gas giants and planetary masses silently ...