Professor Hanington talks about science: water on Mars | Lifestyle

The liquid water on a long trip is always a good thing to find. You may remember that NASA discovered several years ago the possible signs of intermittent flow of liquid water just below the Martian surface where it could be a little warmer and not subject to Evaporation

millions of satellite photographs revealing dry riverbeds and erosional ravines have shown that water was once present on the surface of Mars in the past but, for a reason or another, has practically disappeared. Because the climate of the planet is cold, liquid water would be rare because most of its water is locked in the ice.

When I taught astronomy 101 to GBC, we spent a week covering the fourth planet. Students learned that the surface temperature of Mars on its equator does not reach much more than 80 degrees Fahrenheit, even during the hottest days. Surface probes sent over the last 30 years show an average temperature hovering at 67 degrees Fahrenheit, freezing not only water in the ice, but carbon dioxide in dry ice.

two factors working in tandem. First, the planet has an ultra-thin atmosphere. Any radiant energy received from the Sun is not trapped as it is on the Earth but radiated in space. Second, the planet has a bad position in the lineup. Because it's about 1.5 times farther away from the Sun than the Earth, the energy it receives is only 43% of what we get per square meter.

The discovery of the underground lake was made with the help of MARSIS. orbiter. By transmitting a microwave signal to the planet and examining what is bouncing, the surface and immediate subsurface of the planet can be examined for discontinuities due to the evolution of geology. As a layer of groundwater returns a signal very different from that of a solid bedrock, one can map out the outline of the water deposit.

The researchers used 29 sets of radar images showing an area near one thousand surface that stretched about 12.5 miles across and looked a lot like the lakes that lie beneath them. icecaps of Greenland and Antarctica on Earth. Although MARSIS has not been able to determine the thickness of the water layer, scientists have estimated at least one meter

How much population this underground lake can he bear? It's easy to calculate. Estimates vary, but each person in an average household uses about 80-100 gallons of water a day, most of them being used to pull toilets and take showers and baths. A lake 12 miles in diameter and three feet deep contains 76 billion gallons of water. This could last a colony of a thousand explorers from space two thousand years without recycling!

But, to stay liquid in such cold conditions, perhaps as low as -20 degrees Fahrenheit, it is surmised that the water probably has a lot of salt dissolved in it and that should be filtered, perhaps by a mechanism of reverse osmosis. On Earth, there are underground lakes beneath the Antarctic ice sheet, even though the average annual surface temperature is 76 degrees below zero Fahrenheit. Maybe a pipeline to this reservoir will be built someday to exploit this resource.

Can there be life in this lake?

"It is plausible that the water is an extremely cold and concentrated brine, which would be very difficult for life," says Dr. Claire Cousins, astrobiologist at the University of St Andrews, UK -United. In other words, without the benefit of sunlight to stimulate organic reactions, the prospect of biological activity as we know it is rather bleak. Yet the presence of blind cavefish here on Earth, like the Mexican tetra, living comfortably for millions of years, never feeling the heat of a summer day, makes this lake d & rsquo; Water very intriguing.

Because Mars is in opposition On July 27, when the Earth will move between Mars and the Sun, the planet will appear in the form of an object resembling a very bright and reddish star that shines on the planet. south-east horizon. It will be his brightest for the next 17 years.