Neptune's moon and ring system stand out among the giant planets because of the strange imbalance between its one very large moon and its many tiny moons. Its largest moon, Triton, makes up more than ...

They want most, if not all of those round objects to be considered planets. Some think that all dwarf planets should be planets. That includes Pluto and its moon Charon, Eris, Haumea, Makemake, and ...

For decades, astronomers lumped brown dwarfs into a single category defined by mass alone—too big to be classified as planets but too small to become stars. However, this definition ignores the two ...

The hatch opens and the first thing that hits you is the light. Not the bright white glare you have known your entire life.