Alien Skies pp 126-137 | Cite as

Back to Earth

  • Frédéric J. Pont


There is a set of terrestrial planets that we can study much closer to home. They are separated from us not by space but by time. Our planet has been around for 4.6 billion years, about a third of the total age of the Universe (13.7 billion years). Throughout its long life, it has changed so much that, were we to be transported to one of its past incarnations, it would appear as alien as an exoplanet.


Break Water Lava Flow Free Oxygen Continental Drift Submarine Volcano 
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Copyright information

© Springer Science+Business Media New York 2014

Authors and Affiliations

  • Frédéric J. Pont
    • 1
  1. 1.University of ExeterExeterUK

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