Test results released Friday in a teleconference from Jet
Propulsion Laboratory are not conclusive but are in line with
past studies that found no regular methane on Mars. The results
do stand in contrast to other research such as observations by
Earth-based telescopes that indicated Mars belched thousands of
tons of methane in 2003. On Earth, methane gas is overwhelmingly
a byproduct of life, but it can also be produced by non-
biological processes. Mission scientists will continue to search
for methane. Curiosity has been operating on Mars since its
August landing in a crater.