Space Orbiter Mars Express of the European space Agency has received evidence of the availability of stocks of liquid water under layers of ice and dust in one area of the South pole of Mars. Writes about the opening of the official website of the European space Agency.
That once on the surface of the red planet had liquid water scientists for a long time, implying geological features in the form of ancient dry riverbeds, channels and other geological structures are visible from orbiters. In addition, in tandem with the orbital probes on the surface of the planet there are several Rovers, who also find evidence in favor of “raw” history of the red planet. It is implied at least the existence of separate types of minerals that can only form in the presence of water pressure.
According to scientists, during the existence of Mars (about 4.6 billion years) its climate has changed significantly and today, the water in liquid form cannot stick on the surface of the planet. Therefore, the researchers decided to see if there was liquid water under it.
Planetary scientists have long inclined to the probability of presence of liquid water under the ice caps at the poles. In the end we know that the freezing point can decrease under the pressure of the overlying glacier. In addition, the presence of salts on Mars is able to further reduce the freezing point, allowing to maintain the water in liquid state even at temperatures below freezing.
Until recently, data from the Mars Express specialized radar European space Agency to probe the ionosphere and the deep layers of the Martian surface (MARSIS) looked to scientists unconvincing. To confirm their assumptions, the researchers had to work hard to how to maximize its effectiveness and to give the possibility to collect data in such high resolution, as it is possible in this case.
Penetrating radar uses a technique of sending signals across the planet’s surface and calculates the time required for a signal reflection and return it to the spacecraft. The chemical properties of the elements that are on the path of the signal change it. The signal can be either a dimmer that can speak, for example, the presence of solid rock in his way, or clearer, or even reinforced, that will talk about the high reflectivity of the element that it repelled. Due to this, scientists can determine what is under the surface of the planet.
Map of southern plateau and the area in which the research was conducted
The sensing region width of about 200 km using MARSIS showed that the surface of the South pole of Mars is covered with several layers of ice and dust and a depth of about 1.5 kilometers. A particularly strong enhancement of reflection signal was recorded under the layered deposits within the 20-kilometer zone at a depth of about 1.5 kilometers. After analyzing properties of the reflected signal and examining the composition of the layered deposits, and the expected temperature profile under the surface of this region, scientists came to the conclusion that the MARSIS found under the surface of the pocket with a lake of liquid water. Scientists say that the device could not determine how deep can be the lake, but estimated its depth should be at least several tens of centimeters (this should be the layer of water to be seen MARSIS).
Image with radar MARSIS
“This really qualifies as a lake. Lake, not some kind of melt water that fills some space between the rock and ice, as it occurs in certain areas on Earth,” commented Professor Roberto Orosei from the Italian Institute of astrophysics, who heads the study.
Theoretically, the gain of the signal, which I suspect lake, can give a layer of frozen carbon dioxide or water ice just low temperatures, but the authors reject these assumptions, as these options are not enough in good agreement with the observations.
“The only possible explanation for what we see is liquid water,” said Gulf of Orosei.
“With MARSIS we found out that there is liquid water, it is salty and is in contact with sediments. The ingredients in order that there could be life on the spot, and more MARSIS can not say anything, he can’t answer the question about whether there is life” — said Enrico Flamini, representing the Italian space Agency.
“Assumptions about the presence of liquid water under the polar caps of Mars appeared many years ago. However, to confirm or deny them until now was not possible as I had never managed to discover on Mars, a steady accumulation of liquid water, since the data collected was of very poor quality,” adds Andrea Cichetti, co-author of the study.
With the help of radar examined only a few percent of the southern plateau, and its features allow you to see only large enough accumulation of water.
“This is just one small area. Just imagine that under the surface of Mars may contain many such underground lakes of water.”