BEIJING, May 16 (Xinhuanet) -- NASA is close to deciding on a landing site for its Mars rover Curiosity mission by narrowing the choices to four, media reports said Monday.

Scientists in the close-knit Mars research community get one last chance to make their case this week when they gather before the "judges" — the team running the 2.5 billion U.S. dollar mission that will soon suggest a landing site to NASA, the ultimate decider.

"All four of these places are compelling places on Mars to study. There's not a loser among them," said landing site scientist Matt Golombek of the NASA Jet Propulsion Laboratory, one of the meeting's leaders.

The mission will use rover Curiosity to study whether a selected area will have environmental conditions suitable for life and for preserving evidence about whether extraterrestial life has existed.

Being nuclear-powered, the rover cannot go to a location that has either water or ice within one meter of the surface.

The size of a mini Cooper, Curiosity is scheduled to launch in late November after a two-year delay.