ESA title
Ancient northern ocean on Mars
Science & Exploration

ESA's Mars Express radar gives strong evidence for former Mars ocean

06/02/2012 8706 views 10 likes
ESA / Science & Exploration / Space Science / Mars Express

ESA's Mars Express has returned strong evidence for an ocean once covering part of Mars. Using radar, it has detected sediments reminiscent of an ocean floor within the boundaries of previously identified, ancient shorelines on Mars.

The MARSIS radar was deployed in 2005 and has been collecting data ever since. Jérémie Mouginot, Institut de Planétologie et d'Astrophysique de Grenoble (IPAG) and the University of California, Irvine, and colleagues have analysed more than two years of data and found that the northern plains are covered in low-density material.

"We interpret these as sedimentary deposits, maybe ice-rich," says Dr Mouginot. "It is a strong new indication that there was once an ocean here."

The existence of oceans on ancient Mars has been suspected before and features reminiscent of shorelines have been tentatively identified in images from various spacecraft. But it remains a controversial issue.

Two oceans have been proposed: 4 billion years ago, when warmer conditions prevailed, and also 3 billion years ago when subsurface ice melted, possibly as a result of enhanced geothermal activity, creating outflow channels that drained the water into areas of low elevation.

Mars Express radar investigation
Mars Express radar investigation

"MARSIS penetrates deep into the ground, revealing the first 60–80 metres of the planet's subsurface," says Wlodek Kofman, leader of the radar team at IPAG.

"Throughout all of this depth, we see the evidence for sedimentary material and ice."

The sediments revealed by MARSIS are areas of low radar reflectivity. Such sediments are typically low-density granular materials that have been eroded away by water and carried to their final destination.

This later ocean would however have been temporary. Within a million years or less, Dr Mouginot estimates, the water would have either frozen back in place and been preserved underground again, or turned into vapour and lifted gradually into the atmosphere.

"I don't think it could have stayed as an ocean long enough for life to form."

In order to find evidence of life, astrobiologists will have to look even further back in Mars' history when liquid water existed for much longer periods.

Nevertheless, this work provides some of the best evidence yet that there were once large bodies of liquid water on Mars and is further proof of the role of liquid water in the martian geological history.

"Previous Mars Express results about water on Mars came from the study of images and mineralogical data, as well as atmospheric measurements. Now we have the view from the subsurface radar," says Olivier Witasse, ESA's Mars Express Project Scientist.

"This adds new pieces of information to the puzzle but the question remains: where did all the water go?"

Mars Express continues its investigation.

Contact for further information

Related Links

Pit-chains in Tharsis
Science & Exploration

The pit-chains of Mars – a possible place for life?

05/04/2012 6622 views 16 likes
Read
Ancient northern ocean on Mars
Science & Exploration

ESA's Mars Express radar gives strong evidence for former M…

06/02/2012 8706 views 10 likes
Read
Part of Syrtis Major
Science & Exploration

Mars Express reveals wind-blown deposits on Mars

03/02/2012 3525 views 6 likes
Read
Phlegra Montes on Mars
Science & Exploration

Mountains and buried ice on Mars

02/12/2011 5821 views 15 likes
Read
Battered volcano Tharsis Tholus
Science & Exploration

Battered Tharsis Tholus volcano on Mars

08/11/2011 4923 views 7 likes
Read
Oraibi crater in Ares Vallis
Science & Exploration

Mars Express observes clusters of recent craters in Ares Va…

07/10/2011 2842 views 6 likes
Read
Holden and Eberswalde craters
Science & Exploration

Rare martian lake delta spotted by Mars Express

02/09/2011 7768 views 24 likes
Read
Mars’ northern polar regions
Science & Exploration

Mars’ northern polar regions in transition

05/08/2011 5667 views 12 likes
Read
Conjunction: before, during and after
Science & Exploration

Phobos slips past Jupiter

17/06/2011 5649 views 15 likes
Read
Springtime at Mars’ south pole
Science & Exploration

Springtime at Mars’ south pole

07/06/2011 5138 views 11 likes
Read
Deep fractures on Mars
Science & Exploration

Mars Express sees deep fractures on Mars

06/05/2011 4022 views 8 likes
Read
Neighbouring volcanoes on Mars
Science & Exploration

Neighbouring volcanoes on Mars

01/04/2011 4742 views 11 likes
Read
Elongated crater on Mars
Science & Exploration

The scars of impacts on Mars

04/03/2011 5915 views 7 likes
Read
Arabia Terra on Mars
Science & Exploration

Mars Express puts craters on a pedestal

04/02/2011 3322 views 3 likes
Read
Stereo-1 channel image of Phobos
Science & Exploration

Mars Express close flybys of martian moon Phobos

21/01/2011 10629 views 14 likes
Read
Schiaparelli on Mars
Science & Exploration

Wind and water have shaped Schiaparelli on Mars

10/12/2010 7458 views 13 likes
Read
Phoenicis Lacus on Mars
Science & Exploration

Light and dark in the Phoenix Lake

12/11/2010 2890 views 6 likes
Read
Melas Chasma on Mars
Science & Exploration

Mars: how low can you go?

08/10/2010 3704 views 5 likes
Read
Orcus Patera on Mars
Science & Exploration

Mars’s mysterious elongated crater

27/08/2010 9579 views 24 likes
Read
Magellan Crater on Mars
Science & Exploration

Rocky mounds and a plateau on Mars

28/06/2010 3757 views 8 likes
Read
Science & Exploration

Wet era on early Mars was global

25/06/2010 2997 views 5 likes
Read
Volcanic ash deposits in Meridiani Planum
Science & Exploration

Volcanic ash in Meridiani Planum

12/05/2010 5168 views 10 likes
Read
Part of the Sirenum Fossae region in the Southern Highlands of Mars.
Science & Exploration

Craters young and old in Sirenum Fossae

03/02/2010 3780 views 8 likes
Read
Close to Ma'adim Vallis
Science & Exploration

Craters, lava flows and tectonic features near Ma'adim Vall…

24/07/2009 3792 views 5 likes
Read
Impacts and floods
Science & Exploration

Craters and channels in Hephaestus Fossae

05/06/2009 5433 views 10 likes
Read
Ariadnes Colles, nadir view
Science & Exploration

Chaotic terrain in Ariadnes Colles

24/04/2009 3150 views 17 likes
Read
Rupes Tenuis
Science & Exploration

Ice-covered martian North Pole

06/03/2009 2977 views 7 likes
Read
Euminedes Dorsum
Science & Exploration

The Euminedes Dorsum mountains on Mars

28/11/2008 2902 views 7 likes
Read
Mangala Fossae
Science & Exploration

Lava deposits in Mangala Fossae

26/09/2008 2936 views 9 likes
Read

Related Links