In search of the water of Mars

2000/06/27 Roa Zubia, Guillermo - Elhuyar Zientzia

• Astrofisika

The Mars Global Surveyor probe has sent new photos. In these photos the surface of Mars is observed with great precision, as they are the most accurate images obtained from the orbit. If these photos had been taken on Earth, there would be no doubt that they are remnants left by water. Being Mars there is only suspicion. However, although the explanation is not very simple, it is a reasonable hypothesis.

The idea is not new. Since the red planet has been observed by telescopes, the hypothetical presence of water has been evident. It is relatively close to us, is reddish and is the origin of legends and myths. In addition, according to what we know, to create life water is essential. This feature has made this liquid interesting.

Gian D. Cassini, a French astronomer of Italian origin, saw the white poles of Mars and believed that water could be. In 1877 the Italian astronomer Giovanni Virginio Schiaparelli formed the first map of Mars. On that map they saw canalli and immediately mentioned the water. Moreover, the name of canalli was bad English. Instead of writing Channel (paths created naturally by water), the word channel (artificial channels) was used. Hence, the creations of its inhabitants are disseminated and the fashion of speculation of life outside the Earth emerged. However, these canallis have not been seen again because on Mars it does not exist.

In 1971 NASA's Mariner 9 probe was introduced into the orbit of Mars in order to study the surface. Immediately after maintaining the orbit there was a terrible sandstorm covering the entire planet. At the end of the storm it took more than seven thousand photographs (70% of the surface). In addition to volcanoes and tectonic plates, the images showed traces of water erosion. In the Mars program one of the efforts of the coming years would be to seek water.

According to experts, in Mars there was formerly water, but at some point there was a violent climate change that has led the planet to the current situation. In January 1999, the Mars Polar Lander probe was launched to collect data and find water for climate research. The mission failed in January of this year, as upon landing it did not give any signal. The probe was declared lost.

Characteristics of the planet

Mars is smaller than Earth. Its diameter is about half that of the Earth. The difference in mass between the two is even greater. This means that Mars does not create gravitational zones capable of withstanding a very compact atmosphere. In other words, molecules flee from Mars. It is a fine atmosphere of carbon dioxide and low atmospheric pressure. In these conditions the water does not remain in liquid state for a long time. It evaporates and is also easily spacable.

Evidence of the water remains of the Mariner 9 probe has now been confirmed by the Mars Global Surveyor probe through images taken much closer. But then where has the water gone? Has it evaporated? One answer is that she is buried, but it is not a complete answer. In view of the dry channels of the photos new ideas have been launched. These are relatively new channels, a few million years old, mostly in the southern hemisphere.

NASA scientists propose a model to explain the origin of these channels. On the surface of Mars the water evaporates. Then, by evaporating the first drops that filter from the subsoil, the surrounding soil cools. Groundwater is still frozen. Thus, the accumulated ice presses until the soil breaks. When the ice surges, therefore, it forms the channel, as something similar to the floods here occurs.

According to scientists, water is 100-400 meters from the surface in certain places on the planet. Each of these floods would have 2,500 cubic meters of water. Despite this, the process that starts the movement of water is not of course. If the hypothesis is correct, groundwater could be used to supply manned trips to Mars.

NASA technicians claim that Mars and water are an important moment of research. However, keep in mind that they need publicity to forget the last defeats. The Mars Global Surveyor probe has only brought geology photos and technicians have invented the new hypothesis, but for the moment no water has been found. We will have to wait for the theory to be confirmed.