Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Mars valleys traced back to precipitation

29.06.2018

The surface of Mars bears imprints of structures that resemble fluvial steam networks on Earth. Scientists therefore assume that there must have been once enough water on the red planet to feed water streams that incised their path into the soil. For years, however, scientists have been debating the source from which this water must have originated: was it rainwater that caused streams and rivers to swell? Or did water ice in the soil melt due to volcanic activity, and seep out to form rivers? Each of these scenarios leads to a completely different conclusion about the climatic history of the red planet.

A new study now suggests that the branching structure of the former river networks on Mars has striking similarities with terrestrial arid landscapes. This has been demonstrated in a recent paper published in Science Advances by physicist Hansjörg Seybold from the group of James Kirchner, ETH professor at the Institute for Terrestrial Ecosystems, and planetary specialist Edwin Kite from the University of Chicago.


The central portion of Osuga Valles, which has a total length of 164 km. In some places, it is 20 km wide and plunges to a depth of 900 m.

Photograph: ESA/DLR/FU Berlin, CC BY-SA 3.0 IGO

Valleys eroded mainly by rainwater

Using statistics from all mapped river valleys on Mars, the researchers conclude that the contours still visible today must have been created by superficial run-off of (rain)water. Consequently, the influence of groundwater seepage from the soil can be excluded as a dominant process for shaping these features.

The distribution of the branching angles of the valleys on Mars is very similar to those found in arid landscapes on Earth. According to lead author Seybold, this implies that there must have been a similar hydrological environment with sporadic heavy rainfall events on Mars over a prolonged period of time and that this rainwater may have run off quickly over the surface shaping the valley networks.

This is how river valleys develop in arid regions on Earth. For example, in Arizona, researchers observed the same valley network patterns in a landscape where astronauts are training for future Mars missions. Valleys in arid regions fork at a narrow angle.

The branching angles on Mars are comparatively low. Seybold therefore rules out the influence of groundwater sapping as the major channel forming process on Mars. River networks that are formed by re-emerging groundwater, as found, for example, in Florida, tend to have much wider branching angles between the two tributaries and do not match the narrow angles of streams in arid areas.

Conditions such as those found in terrestrial arid landscapes today probably prevailed on Mars for only a relatively short period about 3.6 to 3.8 billion years ago. In that period, the atmosphere on Mars may have been much denser than it is today. "Recent research shows that there must have been much more water on Mars than previously assumed," says Seybold.

Evaporation made it rain

One hypothesis suggests that the northern third of Mars was covered by an ocean at that time. Water evaporated, condensed around the high volcanoes of the highlands to the south of the ocean and led to heavy precipitation. As a result, rivers formed, which left traces that can still be observed on Mars today.

The big question is where the water has disappeared to over time. "It's likely that most of it evaporated into space. But it could still be found in the vicinity of Mars," says the physicist., " but this is a question for a future space mission".

###

Reference

Seybold HJ, Kite E, Kirchner JW. Branching geometry of valley networks on Mars and Earth and its implications for early Martian climate. Science Advances 2018; 4:eaar6692. DOI: 10.1126/sciadv.aar6692

Media Contact

Hansjoerg Seybold
hansjoerg.seybold@usys.ethz.ch
41-446-338-197

 @ETH_en

http://www.ethz.ch/index_EN 

Hansjoerg Seybold | EurekAlert!
Further information:
https://www.ethz.ch/en/news-and-events/eth-news/news/2018/06/geometrie-von-mars-flusstaelern.html
http://dx.doi.org/10.1126/sciadv.aar6692

Further reports about: Atmosphere ETH Earth Mars heavy rainfall landscapes rainfall events volcanoes

More articles from Physics and Astronomy:

nachricht From the cosmos to fusion plasmas, PPPL presents findings at global APS gathering
13.11.2018 | DOE/Princeton Plasma Physics Laboratory

nachricht A two-atom quantum duet
12.11.2018 | Institute for Basic Science

All articles from Physics and Astronomy >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: A Chip with Blood Vessels

Biochips have been developed at TU Wien (Vienna), on which tissue can be produced and examined. This allows supplying the tissue with different substances in a very controlled way.

Cultivating human cells in the Petri dish is not a big challenge today. Producing artificial tissue, however, permeated by fine blood vessels, is a much more...

Im Focus: A Leap Into Quantum Technology

Faster and secure data communication: This is the goal of a new joint project involving physicists from the University of Würzburg. The German Federal Ministry of Education and Research funds the project with 14.8 million euro.

In our digital world data security and secure communication are becoming more and more important. Quantum communication is a promising approach to achieve...

Im Focus: Research icebreaker Polarstern begins the Antarctic season

What does it look like below the ice shelf of the calved massive iceberg A68?

On Saturday, 10 November 2018, the research icebreaker Polarstern will leave its homeport of Bremerhaven, bound for Cape Town, South Africa.

Im Focus: Penn engineers develop ultrathin, ultralight 'nanocardboard'

When choosing materials to make something, trade-offs need to be made between a host of properties, such as thickness, stiffness and weight. Depending on the application in question, finding just the right balance is the difference between success and failure

Now, a team of Penn Engineers has demonstrated a new material they call "nanocardboard," an ultrathin equivalent of corrugated paper cardboard. A square...

Im Focus: Coping with errors in the quantum age

Physicists at ETH Zurich demonstrate how errors that occur during the manipulation of quantum system can be monitored and corrected on the fly

The field of quantum computation has seen tremendous progress in recent years. Bit by bit, quantum devices start to challenge conventional computers, at least...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

“3rd Conference on Laser Polishing – LaP 2018” Attracts International Experts and Users

09.11.2018 | Event News

On the brain’s ability to find the right direction

06.11.2018 | Event News

European Space Talks: Weltraumschrott – eine Gefahr für die Gesellschaft?

23.10.2018 | Event News

 
Latest News

The dawn of a new era for genebanks - molecular characterisation of an entire genebank collection

13.11.2018 | Life Sciences

Fish recognize their prey by electric colors

13.11.2018 | Life Sciences

Ultrasound Connects

13.11.2018 | Awards Funding

VideoLinks
Science & Research
Overview of more VideoLinks >>>