MARS/ The Mysteries of the Red Planet
Mars never ceases to amaze. A few days ago, an article appeared in the journal Science by a group led by A. S. McEven, Seasonal Flows on Warm Martian Slopes, which reports on very interesting results. The article is based on data collected by the Mars Reconnaissance Orbiter over the last few years. The probe, property of NASA, was launched on August 12, 2005 with the task of collecting information that could demonstrate that water existed on Mars and for a sufficiently long period of time to permit the eventual development of an environment suitable for life. A few days from the sixth anniversary of the launch of the probe, the latest news from the red planet has been published.
The results come from images that demonstrate that, in some rare and isolated areas of the southern hemisphere of the planet, at latitudes 32 to 45 degrees, there are dark traces, about 0.5 to 5 meters wide, similar to small canals. These traces appear at the beginning of the Martian spring, swell during the spring and summer and then are reduced and disappear with the coming of winter and the cold. The observation of this phenomenon happened in areas where the temperature in the warm period reaches 250-300 Kelvin, which is approximately between -23 and 26 degrees Celsius, and on slopes of 25 to 40 degrees towards the North (thus directed towards the equator).
The phenomenon, the authors of the article write, could be explained by the presence of salt water near the surface of the planet, but the results obtained cannot in any way demonstrate the presence of the liquid and so the mechanism that generates the observed phenomenon remains unexplained. In a similar temperature interval, it would be impossible for a flow of pure water to remain in a liquid state and it would be even less possible because of the abundance of CO2 on the planet.
McEven states that the dark traces, of which in some areas there are more than a thousand, are not dark because they are wet with a liquid, but for some other unknown reason. It is a mystery, but a mystery that can be investigated with further observations and experiments.
The possible discovery of water on Mars (whether in a liquid state or not) would be of fundamental importance to understanding the history of the planet, adding elements that could confirm or refute the current or past presence of forms of life and would be of great importance for a mission that could bring man to another planet for the first time. However, it is not possible at this time to arrive at the conclusion that there is water in its liquid state on Mars.
Of course this adds an important piece to the large and ever more detailed puzzle that describes this mysterious planet. However, it is easy to fall into the temptation of sensationalism, sheltering behind the need for communicative simplification. To write that “in the summer on Mars salt water flows like that of the oceans”, as appeared in an important Italian newspaper a few days ago, is a stretch and is not very respectful of the work of those who are dedicating themselves to this research.
(translation by Maria Bond)