North-south geological differences between the residual polar caps on Mars
Article Abstract:
Polar processes can be used as indicators of global climate. The polar regions on Mars are morphologically and climatologically distinctive. It is shown that the residual cap on the south pole is a distinct geologic unit, having striking collapse and erosional topography. It is indicative of depositional and ablational events not recorded in the north or the outlying southern polar layered deposits.
Publication Name: Nature
Subject: Zoology and wildlife conservation
ISSN: 0028-0836
Year: 2000
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Evidence for non-synchronous rotation of Europa
Article Abstract:
Observations made by the Galileo spacecraft present evidence that Europa spins more rapidly than the synchronous rate, or that this was the case in the past. This finding is in alignment with the possibility of a global subsurface ocean. If Europa's interior has a sufficient mass distribution asymmetry to tidally lock the moon towards Jupiter, as the gravity results appear to suggest, but the surface shows signs of asynchronous rotation, then the crust has to be mechanically decoupled from the interior. Decoupling could result from a subsurface ocean or a layer of ductile ice.
Publication Name: Nature
Subject: Zoology and wildlife conservation
ISSN: 0028-0836
Year: 1998
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Bright dunes on Mars
Article Abstract:
Seasonal changes on the surface of Mars may be due to the transport of geological materials by wine. Large wind-formed features such as dunes were seen in images from orbiting spacecraft in the 1970s, but types and sources of aeolian materials could not be identified. New images show that martian dunes have at least two distinct components, with bright areas thought to be composed of soft minerals, such as sulphates.
Publication Name: Nature
Subject: Zoology and wildlife conservation
ISSN: 0028-0836
Year: 1999
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