Earth Day is celebrated annually on April 22. Learn about its origins, global reach, and this year's theme.

Fifty-six years after the first one rallied 20 million people across America, “we need to do things that make us feel more ...

The asteroid Apophis will pass close to Earth in 2029 and will be visible without a telescope, revealing unique changes on ...

NASA says of Apophis passing by that it is likely "an event like this has not happened at any time in recorded human history.

The Apophis asteroid, once feared to hit Earth, is less than three years from making an unprecedented approach toward Earth.

The possibility of life on other planets is one of the biggest mysteries in science. But what would happen if we actually ...

People on the ground in the Eastern Hemisphere will be able to observe the asteroid with their own eyes, weather permitting, ...