New Scientist today has a list of the top ten list of the most controversial pieces of evidence for extraterrestrial life, along with articles on each piece of evidence. It's certainly worth a read, and seems to speak to a more life filled universe than most people think.

1. 1976, The Viking Mars landers detect chemical signatures indicative of life

2. 1977, The unexplained extraterrestrial "Wow!" signal is detected by an Ohio State University radio telescope

3. 1996, Martian "fossils" are discovered in meteorite ALH80041 from Antarctica

4. 2001, A more rigorous estimate of the "Drake equation" suggests that our galaxy may contain hundreds of thousands of life-bearing planets

5. 2001, The red tinge of Jupiter's moon Europa proposed to be due to frozen bits of bacteria, which also helps explain the mysterious infrared signal it gives off

6. 2002, Russian scientists argue that a mysterious radiation-proof microbe may have evolved on Mars

7. 2002, Chemical hints of life are found in old data from Venus probes and landers. Could microbes exist in Venusian clouds?

8. 2003, Sulphur traces on Jupiter's moon Europa may be the waste products of underground bacterial colonies

9. 2004, Methane in the Martian atmosphere hints at microbial metabolism

10. 2004, A mysterious radio signal is received by the SETI project on three occasions - from the same region of space