Earth (planet)

Earth, as seen from space during the Apollo 17 mission.(PD) Image courtesy of: Image Science & Analysis Laboratory, NASA Johnson Space Center

Earth is the only place in the universe known to harbour life. The third planet out from its sun, orbiting within a region neither too hot nor too cold for its inhabitants to exist, in appearance it is a blue-and-white little world, settled in a backwater region of the Milky Way galaxy. Its inhabitants have been described as "mostly harmless".

Look closer, however, and Earth becomes more interesting. An observer who could survive the heavy pollution in the atmosphere would discover that Earth is home to millions of species, with the human one dominant. These creatures have survived through ruthlessly exploiting Earth's resources, warming the Earth as they do so. In all likelihood, Earth will survive the human species, as its fragile ecosystem turns against them - flooding, drought and extreme weather seem to be more common today than in planet's recent past.

References

Adams D (1979) The Hitchiker's Guide to the Galaxy. London: Macmillan. ISBN 0330258648.

See also

• Mars
• Sun
• Galaxy
• Global warming