Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Buried craters and underground ice - Mars Express uncovers depths of Mars

01.12.2005


For the first time in the history of planetary exploration, the MARSIS radar on board ESA’s Mars Express has provided direct information about the deep subsurface of Mars.



First data include buried impact craters, probing of layered deposits at the north pole and hints of the presence of deep underground water-ice. The subsurface of Mars has been so far unexplored territory. Only glimpses of the Martian depths could be deduced through analysis of impact crater and valley walls, and by drawing cross-sections of the crust deduced from geological mapping of the surface.

With measurements taken only for a few weeks during night-time observations last summer, MARSIS - the Mars Advanced Radar for Subsurface and Ionospheric Sounding - is already changing our perception of the Red Planet, adding to our knowledge the missing ’third’ dimension: the Martian interior.


First results reveal an almost circular structure, about 250 km in diameter, shallowly buried under the surface of the northern lowlands of the Chryse Planitia region in the mid-latitudes on Mars. The scientists have interpreted it as a buried basin of impact origin, possibly containing a thick layer of water-ice-rich material.

To draw this first exciting picture of the subsurface, the MARSIS team studied the echoes of the radio waves emitted by the radar, which passed through the surface and then bounced back in the distinctive way that told the ’story’ about the layers penetrated.

These echo structures form a distinctive collection that include parabolic arcs and an additional planar reflecting feature parallel to the ground, 160 km long. The parabolic arcs correspond to ring structures that could be interpreted as the rims of one or more buried impact basins. Other echoes show what may be rim-wall ’slump blocks’ or ’peak-ring’ features.

The planar reflection is consistent with a flat interface that separates the floor of the basin, situated at a depth of about 1.5 to 2.5 km, from a layer of overlying different material. In their analysis of this reflection, scientists do not exclude the intriguing possibility of a low-density, water-ice-rich material at least partially filling the basin.

"The detection of a large buried impact basin suggests that MARSIS data can be used to unveil a population of hidden impact craters in the northern lowlands and elsewhere on the planet," says Jeffrey Plaut, Co-Principal Investigator on MARSIS. "This may force us to reconsider our chronology of the formation and evolution of the surface."

MARSIS also probed the layered deposits that surround the north pole of Mars, in an area between 10º and 40º East longitude. The interior layers and the base of these deposits are poorly exposed. Prior interpretations could only be based on imaging, topographic measurements and other surface techniques.

Two strong and distinct echoes coming from the area correspond to a surface reflection and subsurface interface between two different materials. By analysis of the two echoes, the scientists were able to draw the likely scenario of a nearly pure, cold water-ice layer thicker than 1 km, overlying a deeper layer of basaltic regolith. This conclusion appears to rule out the hypothesis of a melt zone at the base of the northern layered deposits.

To date, the MARSIS team has not observed any convincing evidence for liquid water in the subsurface, but the search has only just begun. "MARSIS is already demonstrating the capability to detect structures and layers in the subsurface of Mars which are not detectable by other sensors, past or present," says Giovanni Picardi, MARSIS Principal Investigator.

"MARSIS holds exciting promise to address, and possibly solve, a number of open questions of major geological significance," he concluded.

Franco Bonacina | alfa
Further information:
http://www.esa.int/SPECIALS/Results_from_Mars_Express_and_Huygens/SEM7ZTULWFE_0.html

More articles from Physics and Astronomy:

nachricht MSU astronomers discovered supermassive black hole in an ultracompact dwarf galaxy
14.08.2018 | Lomonosov Moscow State University

nachricht ASU astrophysicist helps discover that ultrahot planets have starlike atmospheres
13.08.2018 | Arizona State University

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: New interactive machine learning tool makes car designs more aerodynamic

Scientists develop first tool to use machine learning methods to compute flow around interactively designable 3D objects. Tool will be presented at this year’s prestigious SIGGRAPH conference.

When engineers or designers want to test the aerodynamic properties of the newly designed shape of a car, airplane, or other object, they would normally model...

Im Focus: Robots as 'pump attendants': TU Graz develops robot-controlled rapid charging system for e-vehicles

Researchers from TU Graz and their industry partners have unveiled a world first: the prototype of a robot-controlled, high-speed combined charging system (CCS) for electric vehicles that enables series charging of cars in various parking positions.

Global demand for electric vehicles is forecast to rise sharply: by 2025, the number of new vehicle registrations is expected to reach 25 million per year....

Im Focus: The “TRiC” to folding actin

Proteins must be folded correctly to fulfill their molecular functions in cells. Molecular assistants called chaperones help proteins exploit their inbuilt folding potential and reach the correct three-dimensional structure. Researchers at the Max Planck Institute of Biochemistry (MPIB) have demonstrated that actin, the most abundant protein in higher developed cells, does not have the inbuilt potential to fold and instead requires special assistance to fold into its active state. The chaperone TRiC uses a previously undescribed mechanism to perform actin folding. The study was recently published in the journal Cell.

Actin is the most abundant protein in highly developed cells and has diverse functions in processes like cell stabilization, cell division and muscle...

Im Focus: Lining up surprising behaviors of superconductor with one of the world's strongest magnets

Scientists have discovered that the electrical resistance of a copper-oxide compound depends on the magnetic field in a very unusual way -- a finding that could help direct the search for materials that can perfectly conduct electricity at room temperatur

What happens when really powerful magnets--capable of producing magnetic fields nearly two million times stronger than Earth's--are applied to materials that...

Im Focus: World record: Fastest 3-D tomographic images at BESSY II

The quality of materials often depends on the manufacturing process. In casting and welding, for example, the rate at which melts solidify and the resulting microstructure of the alloy is important. With metallic foams as well, it depends on exactly how the foaming process takes place. To understand these processes fully requires fast sensing capability. The fastest 3D tomographic images to date have now been achieved at the BESSY II X-ray source operated by the Helmholtz-Zentrum Berlin.

Dr. Francisco Garcia-Moreno and his team have designed a turntable that rotates ultra-stably about its axis at a constant rotational speed. This really depends...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Within reach of the Universe

08.08.2018 | Event News

A journey through the history of microscopy – new exhibition opens at the MDC

27.07.2018 | Event News

2018 Work Research Conference

25.07.2018 | Event News

 
Latest News

'Building up' stretchable electronics to be as multipurpose as your smartphone

14.08.2018 | Information Technology

During HIV infection, antibody can block B cells from fighting pathogens

14.08.2018 | Life Sciences

First study on physical properties of giant cancer cells may inform new treatments

14.08.2018 | Life Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>