Look to the sky Friday night for the rare chance to see seven planets lined up. The big picture: Saturn, Mercury, Neptune, ...

The astronomical linkup is fairly common and can happen at least every year depending on the number of planets.

Whenever planets are visible in the night sky, they always appear roughly along the same line. This path, known as the ...

Scientists have found a new form of water, called "plastic ice VII," that could possibly exist on other planets. This unusual ...

On Feb. 28, the one-day-old moon will pass in front of Mercury for observers in Australia and the south Pacific, and on March 1 the moon will make a close pass to Venus.

A super rare "blood moon" lunar eclipse will be visible over Mississippi in mid-March. Here's what you need to know about the best times to see it.

High-pressure experiments generated the first direct observation of plastic ice, which has qualities of both crystalline ice and liquid water.