Scientists not ready for 'L' word for Mars

Reports of life on the red planet have been exaggerated (or are being downplayed).

Although Mars Express has been in orbit around Mars since December 2003, scientists have analyzed only a fraction of the data, so it may yet yield the discovery of ammonia. But as of right now, there is no confirmation.

The detection of ammonia would be a powerful indication of life on the red planet, perhaps the most powerful indication, short of discovering microbes or plant life directly.

Mars Express has provided the strongest hint so far of life on Mars, however, when its instruments detected -- and ground-based observations confirmed -- methane in the planet's atmosphere last March.