from The American Heritage® Dictionary of the English Language, 4th Edition

  • n. The outermost region of a planet's atmosphere.
  • n. The outermost layer of the earth's atmosphere, lying above the thermosphere and extending thousands of kilometers into space, from which molecules having sufficient velocity can escape the earth's gravitation.

from Wiktionary, Creative Commons Attribution/Share-Alike License

  • n. the uppermost layer of a planet's atmosphere
  • n. an extremely thin atmosphere, as on Saturn's moon Dione

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

  • n. the outermost atmospheric layer


Sorry, no etymologies found.


  • One surprise is that in the initial data, sodium was seen in the spectroscopic data, and Colaprete said sodium exists in the Moon's tenuous atmosphere called the exosphere, and perhaps something got thermalized during the impact excite the sodium atoms to where strong visible emission lines showed up in the data.

    Moon Impact Data and Images from LCROSS: First Glance | Universe Today

  • What is the nature of that atmosphere, more properly known as an exosphere, and what are its constituents?


  • The strangest thing found in the exosphere was a persistent smear of neutral calcium near the edge of night and day.

    "MAIN" via Steve in Google Reader

  • The observations are expected to yield new insights into how the magnetosphere "force field" works, as well as how thin the uppermost layer of Earth's atmosphere, called the exosphere, actually is, researchers said.

  • (HAARP) radar facility in Ramfjordmoen, Norway this past month has resulted in a "catastrophic puncturing" of our Plant's thermosphere thus allowing into the troposphere an "unimpeded thermal inversion" of the exosphere, which is the outermost layer of Earth's atmosphere.

    Gates of Vienna

  • Moreover, the entire Solar System is well within the "exosphere" of the Sun, actually called a "heliosphere".

    On Thursday, the Legg report will be published along with...

  • BTW, if you are the same Dave who tried to justify "an astronomers" referring to the nonexistent atmosphere of Mercury by refernce to an "exosphere" (on the climate thread) I DID post a reply, which didnt appear.

    On Thursday, the Legg report will be published along with...

  • The second flyby past Mercury is starting to yield new information, including a major new impact basin, an abundance of magnesium in Mercury's "exosphere" and changes to the planet's magnetic field.

    The Lensman's Children

  • Atoms and molecules are knocked off the planet's surface by solar radiation, solar wind bombardment and meteoroid vaporization, forming the stuff of Mercury's thin, elongated atmosphere (or "exosphere"). - latest science and technology news stories

  • Experts who have watched the jump on video say Beamon was somehow able to sweep his trail leg across his body at twice his normal rate as he hit the board, creating an explosive whipping action that launched him into the exosphere.

    Cracking the Long-Jump Code


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