The Hubble Space Telescope has peered at Uranus, left, and Neptune to study the so-called "ice giant" planets, but little is known about their interior composition. - NASA / ESA / M. Showalter / L.

Neptune retrograde will occur from July 2 until Dec. 7. Read on for a deeper meaning behind the cosmic event NASA In astrology, the planet Neptune is said to oversee our dreams, creativity, illusions, ...

A mysterious new world may be hiding in the outer reaches of our solar system. According to arecent study published on arXiv by Amir Siraj of Princeton University and colleagues, a previously unknown ...