Monday, September 28, 2015

The Search for Life on Mars

Today NASA confirmed that it has evidence of liquid water flowing on Mars. The new evidence consists of hydrated salts discovered on downhill streaks on the side of Hale Crater. It is believed that the hydrated salts would lower the freezing point of liquid brine and that the streaks on the crater are therefore evidence of the shallow subsurface flow of briny water.

Entirely by coincidence the European Space Agency has collaborated with CartoDB to release a new map of Mars. This new story map shows the four possible landing sites for the ExoMars 2018 Mission. ESA's ExoMars programme will land a rover on the surface of Mars to search for signs of past and present life.

Where on Mars? is a superbly crafted story map which explains the various criteria being used to pick the perfect landing site for the rover. The map includes a number of different map views of the red planet. Using the forward and back buttons on the map you can progress through the different map layers to learn more about how the final landing site will be chosen.

An altimetry map layer provides a heat map view of elevation on Mars. Because the lander requires a parachute to land on Mars the landing site must be lower than -2km to give the parachute enough time to slow the lander down. If you mouse-over the elevation map a window will open to tell you when you are over an area too elevated to be a potential landing site.

Because the ExoMars Rover is solar powered the landing site must also be within a certain band of latitude straddling the equator. As you progress through the story map this band of latitude is highlighted on the map. Again if you mouse-over the map an information window will open to show you when you are outside this latitude band.

As you progress you can learn more about the geological constraints for the perfect landing site, the landing eclipse (the probability of landing within a given distance of the target site) and some of the important locations close to the potential landing sites.

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