New research has shown that there was liquid water on Mars as recently as 200,000 years ago. The results have been published in the prestigious international scientific journal ICARUS.
“We have discovered a very young crater in the southern mid-latitudes of Mars that shows evidence of liquid water in Mars’ recent past” says Andreas Johnsson at the University of Gothenburg.
The southern hemisphere of Mars is home to a crater that contains very well-preserved gullies and debris flow deposits. The geomorphological attributes of these landforms provide evidence that they were formed by the action of liquid water in geologically recent time.
Evidence of liquid water
When sediment on a slope becomes saturated with water, the mixture may become too heavy to remain in place, leading to a flow of debris and water as a single-phase unit. This is called a debris flow. Debris flows on Earth often cause significant material destruction and even human casualties, when they occur in built-up areas. During a debris flow, a mixture of stones, gravel, clay and water moves rapidly down a slope. When the sediment subsequently stops, it displays characteristic surface features such as lobate deposits and paired levees along flow channels.
It is these landforms that Andreas Johnsson has identified on Mars. The research group has been able to compare the landforms on Mars with known debris flows on Svalbard with the aid of aerial photography and field studies. The debris flows on Mars provide evidence that liquid water has been present in the region.
“Our fieldwork on Svalbard confirmed our interpretation of the Martian deposits. What surprised us was that the crater in which these debris flows have formed is so young,” says Andreas Johnsson of the Department of Earth Sciences, University of Gothenburg.
After the ice age
Crater statistics allowed Andreas Johnsson and his co-authors to determine that the age of the crater to be approximately 200,000 years. This means that the crater was formed long after the most recent proposed ice age on Mars, which ended around 400,000 years ago.
“Gullies are common on Mars, but the ones which have been studied previously are older, and the sediments where they have formed are associated with the most recent ice age. Our study crater on Mars is far too young to have been influenced by the conditions that were prevalent then. This suggests that the meltwater-related processes that formed these deposits have been exceptionally effective also in more recent times,” says Andreas Johnsson, principal author of the article.
Impact in wet ground
The study crater is situated in the mid-latitudes of Mars’ southern hemisphere, superposed on what is known as the rampart ejecta of a nearby larger crater. A rampart ejecta display a “flowerlike” form around the host crater, and scientists have interpreted this as being the result of an impact in wet or ice-rich ground.
“My first thought was that the water that formed these debris flows had come from preserved ice within the rampart ejecta. But when we looked more closely, we didn’t find any structures such as faults or fractures in the crater that could have acted as conduits for the meltwater. It is more likely that the water has come from melting snow packs, when the conditions were favorable for snow formation. This is possible, since the orbital axis of Mars was more tilted in the past than it is today,” says Andreas Johnsson.
Andreas Johnsson, Department of Earth Sciences, University of Gothenburg
Tel.: +46 31 786 2943, Mobile: +46 72 520 5088, e-mail: email@example.com
Ulrika Lundin | idw - Informationsdienst Wissenschaft
Absorbing acoustics with soundless spirals
10.02.2016 | American Institute of Physics
Hot Science of the Cold Universe
10.02.2016 | Max-Planck-Institut für Radioastronomie
The University of Würzburg has two new space projects in the pipeline which are concerned with the observation of planets and autonomous fault correction aboard satellites. The German Federal Ministry of Economic Affairs and Energy funds the projects with around 1.6 million euros.
Detecting tornadoes that sweep across Mars. Discovering meteors that fall to Earth. Investigating strange lightning that flashes from Earth's atmosphere into...
Physicists from Saarland University and the ESPCI in Paris have shown how liquids on solid surfaces can be made to slide over the surface a bit like a bobsleigh on ice. The key is to apply a coating at the boundary between the liquid and the surface that induces the liquid to slip. This results in an increase in the average flow velocity of the liquid and its throughput. This was demonstrated by studying the behaviour of droplets on surfaces with different coatings as they evolved into the equilibrium state. The results could prove useful in optimizing industrial processes, such as the extrusion of plastics.
The study has been published in the respected academic journal PNAS (Proceedings of the National Academy of Sciences of the United States of America).
Exceeding critical temperature limits in the Southern Ocean may cause the collapse of ice sheets and a sharp rise in sea levels
A future warming of the Southern Ocean caused by rising greenhouse gas concentrations in the atmosphere may severely disrupt the stability of the West...
Indications of light-induced lossless electricity transmission in fullerenes contribute to the search for superconducting materials for practical applications.
Superconductors have long been confined to niche applications, due to the fact that the highest temperature at which even the best of these materials becomes...
Researchers at King’s College London and the Wellcome Trust Sanger Institute in the United Kingdom have for the first time demonstrated a direct link between the Wbp2 gene and progressive hearing loss. The scientists report that the loss of Wbp2 expression leads to progressive high-frequency hearing loss in mouse as well as in two clinical cases of children with deafness with no other obvious features. The results are published in EMBO Molecular Medicine.
The scientists have shown that hearing impairment is linked to hormonal signalling rather than to hair cell degeneration. Wbp2 is known as a transcriptional...
09.02.2016 | Event News
02.02.2016 | Event News
26.01.2016 | Event News
10.02.2016 | Physics and Astronomy
10.02.2016 | Life Sciences
10.02.2016 | Power and Electrical Engineering