When you look up at the night sky, planets seem calm and fixed. But a new study shows that nearby planetary systems can be violent and chaotic. Using NASA’s Hubble Space Telescope, astronomers have ...

The formation of Mercury remains an unsolved mystery. The planet closest to the sun has a disproportionately large metallic core—accounting for about 70% of its mass—and a relatively small rocky ...

Astronomers watched a distant star dim for months and found a metal-rich cloud that may be the aftermath of a massive ...

This artistic impression shows the collision of two planetesimals in the young, evolving planetary system of Fomalhaut. NASA’s Hubble Space Telescope has captured the dramatic aftermath of two violent ...

Approximately 4.5 billion years ago, a planet called Theia slammed into the Earth. The impact melted parts of Earth’s mantle and sent a massive cloud of debris into space. Over time, this debris came ...