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 fell back to Earth, but the steel-spring bustle just bounced her back up as high as before.

VOA: special.2009.11.28

This could be a serious problem. The shield protected the spacecraft from burning up from the extreme heat of re-entering the Earth's atmosphere.

VOA: special.2009.06.17

A robot would then pick up rocks and soil, and send them back to earth for testing.

VOA: special.2010.05.25

They said hot melted material flows up from deep inside the Earth through the split.

VOA: special.2010.01.12

He said the Earth is hiring and it was up to them to join together and do what is needed to help save the planet.

VOA: special.2009.06.05

After they land,meteorites can pick up small organisms and chemicals from Earth's environment.

VOA: special.2011.06.22

He not only showed humanity how to get more food from the Earth, he proved that farming has the power to lift up the lives of the poor."

VOA: special.2009.11.10

These communities make up some of the largest living structures on earth.

VOA: special.2010.08.10

This speeded up the spacecraft to reach Earth nine hours sooner.

VOA: special.2009.07.22

A strange odor came up to me from the earth.

VOA: special.2009.11.15

Earthquakes generally occur when the tectonic plates that make up the Earth's crust move suddenly.

VOA: standard.2010.01.13

People aren't talking about setting up Moon bases and throwing rocks at Earth, for example."

VOA: standard.2010.04.21

"What on earth is going on?" Some analysts say discontent is bubbling up from the Pakistani middle class because of U.S.restrictions on visas and increased screening after recent bomb attempts.

VOA: standard.2010.05.06

"What we are doing,folks, we are rolling up our sleeves and we are getting down to business and getting back to the common sense conservative principles that made this country the greatest country on earth, and we are not going to sit down and shut up."

VOA: standard.2010.03.28