Journal of Science

Antarctica’s Effect on Sea Level Rise in Coming Centuries

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Esprit Smith

Jet Propulsion Laboratory, Pasadena, Calif.

  

 

Thwaites Glacier. animation shows projections of ice sheet retreat in Antarctica Thwaites Glacier. Credit: NASA/James Yungel

 

 

There are two primary causes of global mean sea level rise – added water from melting ice sheets and glaciers, and the expansion of sea water as it warms. The melting of Antarctica’s ice sheet is currently responsible for 20-25 percent of global sea level rise.

 

But how much of a role will it play hundreds of years in the future?


 

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The Many Faces of Rosetta’s Comet 67P

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Markus Bauer
European Space Agency, Noordwijk, Netherlands

M. Ramy El-Maarry
University of Colorado

Matt Taylor

ESA Rosetta project scientist 

 

Moving_Boulder_on_Comet_67P.jpg
This image showcases changes identified in high-resolution images of Comet 67P/Churyumov-GerasimenkoA 100 foot-wide (30 meter), 28-million-pound (12.8-million-kilogram) boulder. Several sites of cliff collapse on comet 67P/Churyumov-Gerasimenko A 100 foot-wide (30 meter), 28-million-pound (12.8-million-kilogram) boulder, was found to have moved 460 feet (140 meters) on comet 67P/Churyumov-Gerasimenko in the lead up to perihelion in August 2015, when the comet’s activity was at its highest. Credits: ESA/Rosetta/MPS for OSIRIS Team MPS/UPD/LAM/IAA/SSO/INTA/UPM/DASP/IDA

 

NOTE: Make sure you check 0ut the accompanying Space Photo Exploration page for Comet 67P/Churyumov-Gerasimenko


Images returned from the European Space Agency’s Rosetta mission indicate that during its most recent trip through the inner solar system, the surface of comet 67P/Churyumov-Gerasimenko was a very active place – full of growing fractures, collapsing cliffs and massive rolling boulders. Moving material buried some features on the comet’s surface while exhuming others. A study on 67P’s changing surface was released Tuesday, March 21, in the journal Science.

“As comets approach the sun, they go into overdrive and exhibit spectacular changes on their surface,” said Ramy El-Maarry, study leader and a member of the U.S. Rosetta science team from the University of Colorado, Boulder. “This is something we were not able to really appreciate before the Rosetta mission, which gave us the chance to look at a comet in ultra-high resolution for more than two years.”

 

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