"There really is something very different about how these giant planets form versus how small planets like Earth form." ...

It was not until Johannes Kepler introduced the concept of elliptical orbits that scientists could match their astronomical models to the observed motions of the planets.

For the better part of a century, we believed there were nine planets in our solar system, with Pluto being the farthest from the sun. Since the discovery of more Pluto-sized dwarf planets, that ...

The ringed gas giant Saturn has officially replaced Jupiter as the planet in our solar system with the most moons. The ...

Earth has a nearly circular orbit, but some planets outside our solar system, called exoplanets, have very elliptical orbits.

With the exception of Pluto, planets in our solar system are classified as either terrestrial (Earth-like) or Jovian (Jupiter-like) planets. Terrestrial planets include Mercury, Venus, Earth, and ...