Here's what to know about the short life of what was, for a single human lifetime, the solar system's smallest planet ... to reclassify Pluto as a dwarf planet. The reasoning was that it didn ...

Astronomers have discovered the smallest dwarf galaxy ever seen. It is a mystery how the satellite galaxy of Andromeda survived the blistering conditions of the early universe.

Ceres is one of the smallest dwarf planets in our solar system. A few tricks up its sleeve But that hasn't kept Ceres from shoving its way to the spotlight. The tiny dwarf planet has continued to ...

Why was Pluto reclassified as a dwarf planet? One might think that it’s purely a matter of size. Mercury, the smallest of the ...

These rather small planets are a stone's throw from Earth in galactic terms, but were too small for previous instruments to ...

Each of the planets, labeled b, c, d, and e, has a mass between 20% and 30% of Earth's, making them among the smallest yet ...