Mars and humans on the Red Planet, this is making headlines again. Why? Because water ice is believed to be as little as an inch below the surface of Mars.
A new paper published in Geophysical Research Letters will help by providing a map of this water ice below the surface of Mars, according to a National Aeronautics and Space Administration (Nasa) report.
Nasa will only zero down on a landing site on Mars once it has thoroughly anaslysed where the water ice will be on the Red Planet.
The Nasa report said that any human missions to Mars will have to harvest what’s already available for drinking water and making rocket fuel.
Nasa calls this concept “in situ resource utilisation” and it’s an important factor in selecting human landing sites on Mars.
Satellites orbiting Mars are essential in helping scientists determine the most apropriate places for building the first Martian research station.
The authors of the new paper make use of data from two of those spacecraft, Nasa’s Mars Reconnaissance Orbiter (MRO) and Mars Odyssey Orbiter, to locate water ice that could potentially be within reach of astronauts on Mars.
“You wouldn’t need a backhoe to dig up this ice. You could use a shovel,” the paper’s lead author, Sylvain Piqueux of Nasa’s Jet Propulsion Laboratory in Pasadena, California, said. “We’re continuing to collect data on buried ice on Mars, zeroing in on the best places for astronauts to land.”
Below is a water ice map of Mars. Cool colours are closer to the surface than warm colours; black zones indicate areas where a spacecraft would sink into fine dust; the outlined box represents the ideal region to send astronauts for them to dig up water ice.
This rainbow-colored map shows underground water ice on Mars | Photo credits: Nasa/JPL-Caltech/ASU
ICE WATER – THE TREASURE ON MARS
It’s impossible for liquid water to last in the thin air of Mars; with so little air pressure, it evaporates from a solid to a gas when exposed to the atmosphere.
Martian water ice is locked away underground throughout Mars’s mid-latitudes. These regions near the poles have been studied by Nasa’s Phoenix lander, which scraped up ice, and MRO, which has taken many images from space of meteor impacts that have excavated this ice.
To find ice that astronauts could easily dig up, the study’s authors relied on two heat-sensitive instruments: MRO’s Mars Climate Sounder and the Thermal Emission Imaging System (THEMIS) camera on Mars Odyssey.
Why use heat-sensitive instruments when looking for ice? Buried water ice changes the temperature of the Martian surface. The study’s authors cross-referenced temperatures suggestive of ice with other data, such as reservoirs of ice detected by radar or seen after meteor impacts.
Data from Odyssey’s Gamma Ray Spectrometer, which is tailor-made for mapping water ice deposits, were also useful, Nasa explained.
As expected, all these data suggest a trove of water ice throughout the Martian poles and mid-latitudes. But the map reveals particularly shallow deposits that future mission planners may want to study further.
Below is an animation by Nasa/JPL-Caltech – annotated area of Mars in this illustration holds near-surface water ice that would be easily accessible for astronauts to dig up.
WHERE TO LAND THEN?
A large portion of a region called Arcadia Planitia is the most preferred site in the northern hemisphere of Mars.
The map shows lots of blue and purple in this region, representing water ice less than one 30 centimetre below the surface; warm colours are over 60 centimetre deep. Sprawling black zones on the map represent areas where a landing spacecraft would sink into fine dust.
A comprehensive campaign is being planned to continue studying buried ice across different seasons, watching how the abundance of this resource changes over time.
“The more we look for near-surface ice, the more we find,” MRO Deputy Project Scientist Leslie Tamppari of JPL said. “Observing Mars with multiple spacecraft over the course of years continues to provide us with new ways of discovering this ice.”
(Inputs from Nasa’s website)