Planets Everywhere

Results of a study that looked at 2,000 solar-type stars for five years add 32 exoplanets to the list, pushing the total so far to over 400. The project was designed to look for exoplanets of smaller mass and in fact found several of five times Earth mass and five times Jupiter mass. Many of the exoplanets so far discovered are in fact much bigger than that, simply because bigger bodies are easier to detect.

The study suggests that 40 percent of solar-type stars could have Earth-type planets-- good news for those looking for life in the universe.

Four planets were also found in orbit around small, cool, M-type stars. According to our current model of planetary formation, they shouldn't be there. Clearly, we still have much to learn.