Researchers have long known that there is water in the form of ice on Mars. Now, new research from NASA's Mars rover Curiosity shows that it is possible that there is liquid water close to the surface of Mars.
The explanation is that the substance perchlorate has been found in the soil, which lowers the freezing point so the water does not freeze into ice, but is liquid and present in very salty salt water - a brine. The results are published in the scientific journal Nature.
The image is from 'Hidden Valley' in Gale Crater on Mars. Very fine-grained sediments, which slowly fell down through the water, were deposited right at the bottom of the crater lake. The sediment plates at the bottom are level, so everything indicates that the entire Gale Crater may have been a large lake.
Credit: NASA/JPL, MSSS
In August 2012, the Mars rover Curiosity landed on Mars in the large crater, Gale, located just south of the equator. The giant crater is 154 kilometers in diameter and the rim of the crater is almost 5 kilometers high. In the middle of the crater lies the mountain, Mount Sharp. In over 2½ years, Curiosity has travelled more than 10 km from the landing site towards Mount Sharp and has carried out many studies along the way.
"We have discovered the substance calcium perchlorate in the soil and, under the right conditions, it absorbs water vapour from the atmosphere. Our measurements from the Curiosity rover's weather monitoring station show that these conditions exist at night and just after sunrise in the winter. Based on measurements of humidity and the temperature at a height of 1.6 meters and at the surface of the planet, we can estimate the amount of water that is absorbed. When night falls, some of the water vapour in the atmosphere condenses on the planet surface as frost, but calcium perchlorate is very absorbent and it forms a brine with the water, so the freezing point is lowered and the frost can turn into a liquid. The soil is porous, so what we are seeing is that the water seeps down through the soil. Over time, other salts may also dissolve in the soil and now that they are liquid, they can move and precipitate elsewhere under the surface," explains Morten Bo Madsen, associate professor and head of the Mars Group at the Niels Bohr Institute at the University of Copenhagen.
Riverbed and enormous lake
Observations by the Mars probe's stereo camera have previously shown areas characteristic of old riverbed with rounded pepples that clearly show that a long time ago there was flowing, running water with a depth of up to one meter. Now the new close-up images taken by the rover all the way en route to Mount Sharp show that there are expanses of sedimentary deposits, lying as 'plates' one above the other and leaning a bit toward Mount Sharp.
"These kind of deposits are formed when large amounts of water flow down the slopes of the crater and these streams of water meet the stagnant water in the form of a lake. When the stream meets the surface, the solid material carried by the stream falls down and is deposited in the lake just at the lakeshore. Gradually, a slightly inclined slope is built up just below the surface of the water and traces of such slanting deposits were found during the entire trip to Mount Sharp. Very fine-grained sediments, which slowly fell down through the water, were deposited right at the very bottom of the crater lake. The sediment plates on the bottom are level, so everything indicates that the entire Gale Crater may have been a large lake," explains Morten Bo Madsen.
He explains that about 4.5 billion years ago, Mars had 6½ times as much water as it does now and a thicker atmosphere. But most of this water has disappeared out into space and the reason is that Mars no longer has global magnetic fields, which we have on Earth.
Currents of liquid iron in the Earth's interior generate the magnetic fields and they act as a shield that protects us from cosmic radiation. The magnetic field protects the Earth's atmosphere against degradation from energy rich particles from the Sun. But Mars no longer has a global magnetic field and this means that the atmosphere is not protected from radiation from the Sun, so the solar particles (protons) simply 'shoot' the atmosphere out into space little by little.
Even though liquid water has now been found, it is not likely that life will be found on Mars - it is too dry, too cold and the cosmic radiation is so powerful that it penetrates at least one meter into the surface and kills all life - at least life as we know it on Earth.
Morten Bo Madsen, associate professor and head of the Mars Group at the Niels Bohr Institute, University of Copenhagen, +45 3532-0515, email@example.com
Gertie Skaarup | EurekAlert!
Water - as the underlying driver of the Earth’s carbon cycle
17.01.2017 | Max-Planck-Institut für Biogeochemie
Modeling magma to find copper
13.01.2017 | Université de Genève
Researchers from the University of Hamburg in Germany, in collaboration with colleagues from the University of Aarhus in Denmark, have synthesized a new superconducting material by growing a few layers of an antiferromagnetic transition-metal chalcogenide on a bismuth-based topological insulator, both being non-superconducting materials.
While superconductivity and magnetism are generally believed to be mutually exclusive, surprisingly, in this new material, superconducting correlations...
Laser-driving of semimetals allows creating novel quasiparticle states within condensed matter systems and switching between different states on ultrafast time scales
Studying properties of fundamental particles in condensed matter systems is a promising approach to quantum field theory. Quasiparticles offer the opportunity...
Among the general public, solar thermal energy is currently associated with dark blue, rectangular collectors on building roofs. Technologies are needed for aesthetically high quality architecture which offer the architect more room for manoeuvre when it comes to low- and plus-energy buildings. With the “ArKol” project, researchers at Fraunhofer ISE together with partners are currently developing two façade collectors for solar thermal energy generation, which permit a high degree of design flexibility: a strip collector for opaque façade sections and a solar thermal blind for transparent sections. The current state of the two developments will be presented at the BAU 2017 trade fair.
As part of the “ArKol – development of architecturally highly integrated façade collectors with heat pipes” project, Fraunhofer ISE together with its partners...
At TU Wien, an alternative for resource intensive formwork for the construction of concrete domes was developed. It is now used in a test dome for the Austrian Federal Railways Infrastructure (ÖBB Infrastruktur).
Concrete shells are efficient structures, but not very resource efficient. The formwork for the construction of concrete domes alone requires a high amount of...
Many pathogens use certain sugar compounds from their host to help conceal themselves against the immune system. Scientists at the University of Bonn have now, in cooperation with researchers at the University of York in the United Kingdom, analyzed the dynamics of a bacterial molecule that is involved in this process. They demonstrate that the protein grabs onto the sugar molecule with a Pac Man-like chewing motion and holds it until it can be used. Their results could help design therapeutics that could make the protein poorer at grabbing and holding and hence compromise the pathogen in the host. The study has now been published in “Biophysical Journal”.
The cells of the mouth, nose and intestinal mucosa produce large quantities of a chemical called sialic acid. Many bacteria possess a special transport system...
10.01.2017 | Event News
09.01.2017 | Event News
05.01.2017 | Event News
17.01.2017 | Earth Sciences
17.01.2017 | Materials Sciences
17.01.2017 | Architecture and Construction