The number of planets that orbit the sun depends on what you mean by “planet,” and that’s not so easy to define ...

Stargazers will be treated to a rare seven-planet alignment in February. This is what scientists hope to learn.

Some scientists are throwing out this mind-bending idea that dinosaurs might still be kicking it on other planets out there. We're talking about planets with conditions similar to Earth, where life ...

UK researchers have confirmed the existence of a “super Earth” located 20 light-years away that could reveal the existence of ...

Six of our cosmic neighbors are expected to line up across the night sky tonight, in what has been dubbed a "planetary parade ...

Six planets are parading across the sky, appearing as some of the night's brightest stars. A few easy tips can help you ...

"The other patchiness is that it's patchy in time, so it appears to turn on and off." Other planets, such as Mars, adopt a "stagnant lid" configuration. These planets have convective mantles ...

Stargazers will be treated to a rare alignment of seven planets on 28 February when Mercury joins six other planets that are already visible in the night sky. Here's why it matters to scientists.