Subscribe to our free daily newsletters
. 24/7 Space News .

Subscribe to our free daily newsletters

Possible Mars Shoreline Found
 Providence - Dec. 9, 1999 - In an article to be published in Science magazine Dec. 10, 1999, Brown University planetary geologist James Head and five colleagues present topographical measurements which they say are consistent with an ocean that dried up hundreds of millions of years ago. The measurements were taken by the Mars Orbiter Laser Altimeter, an instrument aboard the unmanned spacecraft Mars Global Surveyor which is circling the planet.

Head's team set out to test the hypotheses of scientists who suggested the possibility of oceans on Mars in 1989 and 1991. The team used data from the Mars Orbiter Laser Altimeter, which beamed a pulsing laser to Mars' surface.

In this topographic portrayal of Mars, above, the northern lowlands are occupied by an ocean (blue) whose shoreline is placed at the position of Contact 2, the line that Parker and co-workers interpreted as an ancient shoreline. Thus, this view shows Mars as it might have looked mid-way through its history according to the oceans hypothesis. The Tharsis region, with numerous very large shield volcanoes is seen in the central part of the globe. In the upper right, many channels flow into the northern lowlands at Chryse Planitia. Credit: MOLA Team. Rendering by Peter Neivert, Brown University.

Scientists measured the time it took for the laser to return to the satellite; the laser traveled a shorter length of time from mountain peaks and longer from craters. MOLA is the first instrument to provide scientists the information required to construct a topographic map of the entire surface of the planet.

For years, scientists have known about channels in which water once flowed into the northern lowlands on the surface of Mars. "The question is whether it collected in large standing bodies," Head said. "This is the first time we could get instruments to comprehensively test these ideas."

According to Head, the team has found four types of quantitative evidence that points to the possible ancient ocean:

  • The elevation of a particular contact (the border between two geological units, such as where one type of surface meets another) is nearly a level surface, which might indicate an ancient shoreline.

  • The topography is smoother below this possible ancient shoreline than above it, consistent with smoothing by sedimentation.

  • The volume of the area below this possible shoreline is within the range of previous estimates of water on Mars.

  • A series of terraces exists parallel to the possible shoreline, consistent with the possibility of receding shorelines.

The results "should make all of us think more seriously about the possibility of the presence of large-scale standing bodies of water on Mars, big lakes and oceans," Head said. "We can't think of anything else to explain these things. They merit much closer scrutiny."

Head's team concludes that further tests are necessary, including analysis of meteorites from Mars and of landing sites, checking for the presence of salts that may be related to former oceans.

The importance of determining whether there were ancient oceans -- and life -- on Mars is that scientists may be able to learn more about long-term climate change and why climate changed on Mars, which has relevance to the future of the Earth, Head said.


Thanks for being here;
We need your help. The SpaceDaily news network continues to grow but revenues have never been harder to maintain.

With the rise of Ad Blockers, and Facebook - our traditional revenue sources via quality network advertising continues to decline. And unlike so many other news sites, we don't have a paywall - with those annoying usernames and passwords.

Our news coverage takes time and effort to publish 365 days a year.

If you find our news sites informative and useful then please consider becoming a regular supporter or for now make a one off contribution.

SpaceDaily Contributor
$5 Billed Once

credit card or paypal
SpaceDaily Monthly Supporter
$5 Billed Monthly

paypal only

Memory Foam Mattress Review
Newsletters :: SpaceDaily :: SpaceWar :: TerraDaily :: Energy Daily
XML Feeds :: Space News :: Earth News :: War News :: Solar Energy News

The content herein, unless otherwise known to be public domain, are Copyright 1995-2016 - Space Media Network. All websites are published in Australia and are solely subject to Australian law and governed by Fair Use principals for news reporting and research purposes. AFP, UPI and IANS news wire stories are copyright Agence France-Presse, United Press International and Indo-Asia News Service. ESA news reports are copyright European Space Agency. All NASA sourced material is public domain. Additional copyrights may apply in whole or part to other bona fide parties. Advertising does not imply endorsement, agreement or approval of any opinions, statements or information provided by Space Media Network on any Web page published or hosted by Space Media Network. Privacy Statement All images and articles appearing on Space Media Network have been edited or digitally altered in some way. Any requests to remove copyright material will be acted upon in a timely and appropriate manner. Any attempt to extort money from Space Media Network will be ignored and reported to Australian Law Enforcement Agencies as a potential case of financial fraud involving the use of a telephonic carriage device or postal service.