Journal of Science

New Study Challenges Long-Held Theory of Fate of Mars’ Water

Posted on

Grey Hautaluoma / Alana Johnson
NASA Headquarters, Washington
grey.hautaluoma-1@nasa.gov / alana.r.johnson@nasa.gov

Andrew Good
Jet Propulsion Laboratory, Pasadena, Calif.
andrew.c.good@jpl.nasa.gov

This global view of Mars is composed of about 100 Viking Orbiter images. Credit: NASA/JPL-Caltech/USGS

The new science results indicate that a large quantity of the Red Planet’s water is trapped in its crust rather than having escaped into space.

Billions of years ago, according to geological evidence, abundant water flowed across Mars and collected into pools, lakes, and deep oceans. New NASA-funded research shows a substantial quantity of its water – between 30 and 99% – is trapped within minerals in the planet’s crust, challenging the current theory that due to the Red Planet’s low gravity, its water escaped into space.

Early Mars was thought to have enough water to have covered the whole planet in an ocean roughly 100 to 1,500 meters (330 to 4,920 feet) deep – a volume roughly equivalent to half of Earth’s Atlantic Ocean. While some of this water undeniably disappeared from Mars via atmospheric escape, the new findings, published in the latest issue of Science, conclude it does not account for most of its water loss.

Read the rest of this entry »

Antarctica’s Effect on Sea Level Rise in Coming Centuries

Posted on Updated on

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?


 

Read the rest of this entry »

The Many Faces of Rosetta’s Comet 67P

Posted on Updated on

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.”

 

Read the rest of this entry »