Water is essential for the survival of life, as we know it. Since the colonization of Mars is on the agenda of most of the space agencies like NASA, and ESA, the availability of water on the distant planet was a major constraint that had to be resolved. The possible discovery of water in liquid form on the red planet is a positive sign. ESA can take credit for this because the possible presence of water was discovered by MARSIS, a radar instrument on board the European Space Agency's (ESA) Mars Express orbiter.

BBC reports that the body of what the scientists suspect is water is below the south polar ice cap of Mars at a depth of 1.5-kilometer and is about 20-Km across.

The depth of the 'water' is estimated to be about one meter. These are based on preliminary findings of the Mars Express orbiter.

The shape of future Mars missions

The search for water on Mars has always been a priory because life depends on it and earlier research had found telltale signs of water on the surface. NASA's Curiosity rover found lake beds that indicated the presence of water in the past. However, the revelation of the Mars Express orbiter can be considered to be a milestone in man’s mission to conquer the red planet.

However, according to ABC Net AU, whether the Martian subsurface lake is mostly pure water or sludgy sediment remains to be seen.

It will be necessary to evaluate the quality of the water available on Mars. The findings reveal that it is some sort of liquid form. This is impossible when temperatures are in the range of -10 and -30 Celsius.

Obviously, the precious substance is likely to have salts dissolved in it. In order to establish the usefulness of this find, a robot will probably have to be sent there to drill through 1.5-Km of ice to reach the source of water and take samples for analysis. But BBC noted that "while the findings suggest water is present, they don't confirm anything further."

Mystery of water on Mars deepens

Scientists are excited about the discovery of water on the red planet by Mars Express spacecraft which had been designed to search for underground water.

It transmitted pulses of radio waves below the surface and measured their reflections. Scientists are keen to know whether this is a one-off find or if there are multiple such subterranean lakes.

According to ABC News, Gretchen Benedix, an astrogeologist at Curtin University who wasn't involved in the study, has said that "based on what we know about how water behaves, it can't exist [as a liquid] on the surface of Mars."

Of course, there is a similar body of water on Earth. It is Lake Vostok, a freshwater lake that lies beneath the ice of East Antarctica. It is nearly 250 kilometers long and is buried nearly four kilometers below the surface. The discovery of water on the planet Mars will be an impetus the for colonization of Mars by NASA, ESA and others.