All of our solar system’s planets are lining up to parade through the night sky at once. This extraordinary celestial event will see the sky scattered with seven visible planets in what is known ...

Astronomers have discovered the earliest seeds of rocky planets forming in the gas around a baby sun-like star, providing a precious peek into the dawn of our own solar system.

Stars passing close to the sun could cause planets to collide, including with Earth, or even be ejected as rogue planets, new simulations show.

After a decade-long search, some scientists say a growing number of clues point to the existence of a hidden planet in the Kuiper Belt beyond Neptune — and they may soon have the opportunity to ...

International astronomers have for the first time witnessed the birth of a planetary system beyond Earth's sun that could one day resemble our own.