The atmosphere is about twenty-percent oxygen and eighty percent nitrogen from Earth's surface to where space begins at one-hundred-twenty kilometers up.

VOA: special.2011.04.06

She says that Earth Day is still very much about activism and fighting for the environment on a local level.

VOA: special.2010.04.21

On Earth Day, the artist and building designer Maya Lin will launch a Web site about the Earth's endangered plants and animals.

VOA: special.2010.04.21

And,he says the discovery will add to what scientists know about Earth's changing climate.

VOA: special.2009.05.12