MUMBAI - NASA scientist Amitabh Ghosh said on Friday that though the discovery of liquid water on Mars opens up immense possibilities, colonization of the red planet is still a distant possibility. "Among the things that need to be considered are the quality of the liquid water there - or for that matter on Pluto and some of the moons of Jupiter or Saturn - and the cost involved to recover it and make it fit for human consumption," Ghosh,