Astronomers have cataloged thousands of exoplanets, and a pattern keeps showing up: Around most stars, the most common ...

A solar conjunction occurs as Venus' orbit carries it into alignment with the sun and Earth. Venus will align with the sun ...

The International Astronomical Union defines a planet as a celestial body that orbits the sun, is massive enough that gravity has forced it into a spherical shape, and has cleared away other objects ...

Thanks to the discovery of thousands of exoplanets to date, we know that planets bigger than Earth but smaller than Neptune ...

Here's how the astronomical phenomenon influences our planet—from the length of our seasons to the way Earth moves through ...

Pluto's days, though they drag on a bit at around 153 hours, are nothing compared to its years. Pluto's orbit takes 248 Earth ...

A NEWLY discovered rogue planet without a host star like the sun to orbit around has been detected dashing through space on ...

Mercury has long baffled astronomers because it defies much of what we know about planet formation. A new space mission ...

Venus reaches greatest brilliancy in the evening sky on Sept. 19 and in the morning sky on Nov. 29. In late September through ...