Simulations show that the stars’ tug could send Mercury, Venus or Mars crashing into Earth — or let Jupiter eject our world from the solar system.

In about 5 billion years, the Sun will run out of hydrogen at its core. This will make it swell up into a red giant, as it ...

Scientists have discovered a colossal object approximately 435 miles wide in the frigid outer reaches of our solar system, ...

The lone planet confirmed to be in the system is squeezed in between the two, orbiting at a distance similar to Earth's ...

Using the Kepler space telescope, the agency had discovered an exoplanet the size of Earth located in the habitable zone of another star. The planet was the first of a similar size to Earth ...

In the cold, dark outskirts of planetary systems far beyond the reach of the known planets, mysterious gas giants and ...

A half-ton spacecraft launched by the Soviet Union 53 years ago is expected to fall back to Earth this weekend.