Alien life? Just watch this space, say scientists
Published 09/12/2010 | 05:00
SCIENTISTS are becoming more convinced that there is alien life, as a handful of recent discoveries make it seem more likely that we are not alone in the universe.
In the past several days, scientists have reported that there are three times as many stars as they previously thought.
Another group of researchers discovered that a microbe can live on arsenic, expanding our understanding of how life can thrive in the harshest environments. And earlier this year, astronomers for the first time said they'd found a potentially habitable planet.
"The evidence is getting stronger," said Carl Pilcher, director of NASA's Astrobiology Institute, which studies the origins, evolution and possibilities of life in the universe. "I think anybody looking at this evidence will say, 'There's got to be life out there'."
There are several possible settings for such a discovery:
- Mars -- The red planet has water, which is key to life, underground, and it used to have even more. Scientists think there's a good chance microbes could be living there, although robot rovers have not found such evidence.
- Europa -- This moon of Jupiter has radiation on its surface that would kill life. But there is a chance that microbes live in the liquid part under the frozen ocean surface, perhaps near hydrothermal vents.
- Enceladus -- This tiny moon of Saturn has supersonic plumes of gas and dust shooting from its surface that indicate it could have all-important liquid water.
- Titan -- Saturn's largest moon has liquid oceans, but they are likely to comprise methane.
- A planet outside our solar system. It is possible that astronomers could detect an atmosphere on such a planet that could only be explained by photosynthesis or other biological processes.
- Earth -- Scientists could find life that came on a meteorite or comet.
- In radio signals -- Scientists are scanning for alien transmissions from space.