The eight planets in our solar system (yes, it's still weird for me to write "eight," too) orbit the sun in roughly circular paths, although they're ever-so-slightly ellipses instead of circles. A new ...

How does a planet’s size influence its orbit around its parent star? This is what a recent study published in the Proceedings of the National Academy of Sciences hopes to address as a team of ...

The shape of a planet's orbit is one of its fundamental properties, along with its size and distance from its host star. Earth has a nearly circular orbit, but some planets outside our solar system, ...

Studying the orbits of thousands of exoplanets shows that large planets tend to have elliptical orbits, while smaller planets tend to have more circular orbits. This split coincides with several other ...

EVANSTON, Ill. — Except for the fact that we call it home, for centuries astronomers didn’t have any particular reason to believe that our solar system was anything special in the universe. But, ...

As planetary systems evolve, gravitational interactions between planets can fling some of them into eccentric elliptical orbits around the host star, or even out of the system altogether. Smaller ...

The first exoplanet ever discovered in 1995 was what we now call a “hot Jupiter”, a planet as massive as Jupiter with an orbital period of just a few days. Today, hot Jupiters are thought to have ...