The Red Planet of War has become a little friendlier this week. Detailed observations of the European Space Agency's Mars Express orbiter have shown that there is a large aquatic lake below the planet's south pole cap.
This is exciting news for the future exploration of our neighboring planet, where the first manned mission was sent. Astronauts to Mars and safe return to Earth are planned for the mid-2030s, maybe 17 years.
Liquid water on a long journey is always a good thing to find. You may recall earlier NASA research several years ago, which found evidence of intermittent liquid water just below the surface of Mars, where it could have been slightly warmer and not evaporated.
Seabeds As Researched by Curiosity's Rover Millions of satellite images showing dry riverbeds and erosion canyons have shown that water used to be on the surface of Mars but has virtually disappeared for some reason. As the climate of the planet is cool, liquid water would be rare, because most of the water is trapped in ice.
When I taught Astronomy 1
Such cold temperatures are the result of two factors working in tandem. First, the planet has an ultra-thin atmosphere. Any radiant energy received by the sun is not captured as if on earth, but radiated back into space. Second, the planet has a bad position in the lineup. Because it is about 1.5 times as far from the sun as Earth, the energy it absorbs is only 43 percent of what we get per square meter.
The discovery of the underground lake was made with MARSIS, a radar aboard the Orbiter. By radiating a microwave signal to the planet and examining what is rebounding, the planet's surface and immediate surface can be examined for discontinuities due to altered geology. Since a layer of subterranean water returns a distinctly different signal than a solid bedrock, a map of the outline of the water deposit could be made.
The researchers used 29 radar images that showed a region nearly one mile below the surface. The surface stretched over 12.5 miles and was very similar to the lakes found under the ice sheet of Greenland and Antarctica on Earth. Although MARSIS was unable to determine how thick the water layer might be, the scientists estimated it to be at least one meter high.
How much population can this underground lake support? That's easy to calculate. Estimates vary, but each person in an average household consumes about 80-100 gallons of water a day, most of which used to flush the toilet and showers and baths. A lake 12 miles across and three feet deep holds 76 billion gallons of water. This could survive a colony of a thousand space explorers for two thousand years without recycling!
But to remain liquid in such cold conditions, perhaps at minus 20 degrees Celsius, it is believed that the water probably has a lot of salt dissolved in it and that might have to be filtered out by a reverse osmosis mechanism. It is known that subterranean lakes exist beneath the Antarctic ice cover, although the average annual surface temperature is 76 degrees below zero Fahrenheit. Maybe someday a pipeline will be built to that reservoir to tap into this resource.
Could there be life in this lake?
"It is plausible that the water can be an extremely cold and concentrated saline solution, which would be a challenge to life," Dr. Claire Cousins, astrobiologist from St Andrews University, UK. In other words, without the benefit of sunlight to stimulate organic responses, the prospect of some biological activity as we know it is rather weak. Still, the presence of blind cave animals here on Earth, like the Mexican Tetra, which has been living comfortably for millions of years and never feels the warmth of a summer day, makes this water lake very intriguing.
Because Mars is in Opposition On July 27, as the Earth moves between Mars and the Sun, the planet appears as a very bright and reddish star-like object shining over the southeastern horizon. This will be the brightest for the next 17 years.