Mars has the largest known volcanoes in the solar system, which show that once was a lot geologically active. But until now available evidence suggests that the period of volcanic activity on the planet ended millions of years ago – these massive caldera have been dormant for a very long time.
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But now it seems that it can not be after all – there may still be some residual activity deep underground, according to a new article in Geophysical Studies . From the report summary:
The latest radar observations from the Mars Express space agency of the European Space Agency have been interpreted as proof of melting under the ice of the southern pole on Mars. We model the temperatures in the underground surface to determine the necessary conditions for reaching liquid water at the base of the ice cap. Salts lower the melting point of ice, with calcium perchlorate generating the lowest temperatures at which melting can be achieved. However, even if there are local concentrations of large quantities of these salts at the base of the southern polar ice, typical Martian conditions are too cold to melt the ice. We find that the local source of heat in the Earth's crust is needed to raise temperatures, and a magma chamber within 10 kilometers (6 miles) of ice can provide such a heat source. This result suggests that if the interpretation of the liquid water of the observations is true, Mars's magmatism may have been active very recently. Horizontal white line, shorter thick blue line "width =" 800 "height =" 574 "srcset =" http://en.es-static.us/upl/2019/02/subsurface-lake-Mars-2018. jpg 800w, http://en.es-static.us/upl/2019/02/subsurface-lake-Mars-2018-300×215.jpg 300w, http://en.es-static.us/upl/2019/ 02 / subsurface-lake-Mars-2018-768×551.jpg 768w, http://en.es-static.us/upl/2019/02/subsurface-lake-Mars-2018-640×459.jpg 640w, http: // en.es-static.us/upl/2019/02/subsurface-lake-Mars-2018-190×136.jpg 190w, http://en.es-static.us/upl/2019/02/subsurface-lake-Mars -2018-140×100.jpg The world's first liquid water lake found on Mars The bright horizontal function of this image is the ice surface of Mars. Southern polar deposits – layers of ice and dust – is seen at a depth of about one mile (1.5 km), and below is a base layer that is even brighter in some areas than the blue reflection surface reflections, and the analysis of the reflected signals implies liquid water. Image using ESA / NASA / JPL / ASI / Univ. Rome; R. Orosei et al.
The findings of the study relate to those from a previous article last year, which provides evidence of a large underground lake for liquid water currently under the southern polar ice cap. The new study says that for such a lake to exist, there must be a source of heat deep beneath the surface – in fact, the recent magmatic activity over the last few hundred thousand years. This is very recent geological, and such warmth can still exist today. Michael Sory, a research fellow at the Lunar and Planetary Laboratory (LPL) at the University of Arizona and co-author of the new document, admits that the new document will be the cause of some debate:
Different people can go differently with this , and we really are interested in seeing how the community responds to this.
The big question, of course, is what this can mean for the search for life. If there is liquid water and a heat source, it will greatly increase the chances of some kind of life – though probably still just a microbe – that exists below the surface. According to Ali Braham, post-doctoral assistant at LPL and co-lead author of the new document:
We believe that if there is any life, it probably has to be protected from the surface of the radiation. If magmatic processes still exist today, they may be more common in the recent past and could provide more widespread basal melting. This could provide a more favorable environment for liquid water and thus, perhaps, life.
A liquid pond under the South Pole would not be too surprising, as they exist under the Earth's polar hats. But scientists are not sure how they will remain liquid on Mars, as the planet is usually much colder than the Earth. As Sorrie remarked:
We thought there was plenty of room to know if it was real, what kind of environment must melt ice in the first place, what temperatures would you need, what kind of geological process would you need? Because under normal conditions it has to be too cold.
So, if the water really is there, as it was announced last year, what's holding it liquid? The new paper research team has modeled the experiments on the underground surface of Mars – in particular, whether salt alone is sufficient. They came to the conclusion that salt alone would probably not be able to raise the temperature sufficiently at the base of the ice cap, and that additional heat would be needed.
So where does that heat come from? The most plausible source will be volcanic activity underground – a magma camera under the ice cap. The team calculated that the magma had risen to the surface from a depth of under 300,000 years but did not reach the surface but remained in the chamber. The warmth of the camera melted the bottom of the ice cap, forming the lake. But most importantly, it will still have to provide that heat today not just hundreds of thousands of years ago. As Bramson notes:
This means that inside the Mars there is still an active formation of a magma chamber, and today it is not just cold, some dead place inside.