"The life on Mars issue has recently undergone a paradigm shift," said Ian Wright, an astrobiologist at the Planetary and Space Sciences Research Institute at the Open University in Britain, "to the extent now that one can talk about the possibility of present life on Mars without risking scientific suicide."
Most of this excitement stems from work done by Vittorio Formisano, head of research at Italy's Institute of Physics and Interplanetary Space, which suggests that there is evidence of the presence of formaldehyde in the atmosphere. Apparently, this is a possible indicator of life on the planet.
With no known geological source of formaldehyde on Mars, it's clear where Formisano's suspicions lie.
"I believe there is extremely high probability that microbial subsurface life exists on Mars," he said, while acknowledging that although he believes in Martian life, he can't yet prove it.