Are eight planets enough? While Mars and Saturn dominate the evening sky, Venus and Jupiter pass near each other late in the month.

A quick guide to planets, including the eight in our solar system, how they form, and how many could be in the universe.

It joins seven other planets circling a star roughly 2,500 light-years away, which means the Kepler-90 system ties our own planetary family for hosting the most known worlds.

A new simulation suggests that planets orbiting a pair of stars may be plentiful, and many of those worlds could be suitable for life.

The discussion underscored how citizen scientists, by contributing thousands of data points from around the world, are ...