Washington, Sep 30: While the world is going gaga over the presence of flowing brine or salty water on the Red Planet, questions are now being asked why the US space agency did not direct its Curiosity rover to the place where water proofs were recorded for a closer look.
The place where Mars Reconnaissance Orbiter (MRO) spotted signs of liquid water is a mere 50 km from where Curiosity is currently exploring the land.
According to the website NPR.org, there may be two reasons for not sending Curiosity to click the perfect water picture.
"The farthest Curiosity has driven in a day is about 150 metres. So even with no obstacles in the way and no traffic, it would take about a year for the rover to get there," the NPR report said on Wednesday.
The other reason may come as a surprise for you.
Since Curiosity may still be carrying some bacterial samples from the Earth, NASA may not want them to get mixed with possible bacteria or some single cell organism that the salty water on the Red Planet may be harbouring.
Curiosity, like other Mars rovers, is not a life-detection mission so these are directed to stay away from places where there may be water.
"In other words, NASA is not only concerned about us contaminating some other planet - it's also concerned about some other planet contaminating us," the report added.
Curiosity has been working on Mars since early August 2012.
Adding to the growing literature on possible life conditions on the Red Planet, Curiosity found in April this year that it is possible that there is liquid water close to the surface of Mars.
The explanation was that the substance calcium perchlorate has been found in the soil which lowers the freezing point so the water does not freeze into ice, but is liquid and present in very salty water - brine.
Curiosity has also made the first detection of nitrogen on the surface of Mars, released during heating of Martian sediments.
The nitrogen was detected in the form of nitric oxide, and could be released from the breakdown by heating of nitrates, or a class of molecules that contain nitrogen in a form that can be used by living organisms.
The discovery adds to the evidence that ancient Mars was habitable for life.