At 500 miles up, by contrast, debris will orbit for decades.
At 17,500 miles an hour, he will orbit the earth 16 times a day.
Once a fact, an assertion, a quote, or a meme has been launched into cyberspace, it will orbit there forever.
MAVEN will orbit Mars every 4.5 hours and get as close as 150 km (90 miles) to its surface.
If all goes well†, the uncrewed spacecraft will orbit the Earth twice before landing in the Pacific Ocean.
The first mission-a pair of spacecraft that will orbit the planet-is scheduled to be launched next year.
The six-ton instrument, seven times more powerful than the Hubble telescope, will orbit 940,000 miles from Earth.
As well as NASA's rovers, an international mission called Mars Express, backed by the European Space Agency, will orbit the planet and send down a British lander.
Along the way it will drop off a Chinese satellite that will orbit Mars to study its surface, atmosphere, magnetic fields and other processes.
MOSTLY MOZART FESTIVAL Following the pattern of recent years, Mozart will be the star around which a veritable solar system of other composers will orbit.
Next year China is likely to launch a probe that will orbit the moon (a feat achieved only by Russia, America and Japan).
