Unformatted text preview: ago. 6. Outflow Channels- Surface feature on Mars, evidence that liquid water once existed there in great quantities; believed to be the relics of catastrophic flooding about 3 billion years ago. Found only in the equatorial regions of the planet. 7. Permafrost- Layer of permanently frozen water ice believed to lie just under the surface of Mars. 8. Primary Atmosphere- The chemical components that would have formed Earth’s atmosphere. 9. Secondary Atmosphere- the chemicals that composed Earth’s atmosphere after the planet’s formation, once volcanic activity out gassed chemicals from the interior. 10. Runaway Greenhouse Effect- A process in which the heating of a planet leads to an increase in its atmosphere’s ability to retain heat and thus to further heating, causing extreme changes in the temperature of the surface and the composition of the atmosphere....
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- Fall '06
- Astronomy, surface feature, Scarp- Surface