Astronomers have discovered a new world circling the outer edges of our solar system. So far, there are only four known ...

The planets in our solar system, varied as they are, represent only a minuscule part of a large, broad spectrum of planetary scale and temperature," he said. "Even very similar exoplanets could ...

Astute skywatchers may have already seen the striking line of planets across the night sky in January. This week Mercury joins the queue. Now every other world in our solar system will be visible ...