Thursday, April 26, 2007

The Life outside Earth

I think that by now everyone has added a new name in the General Knowledge memory - Gliese 581 c. It's not only the name of a newly discovered planet having an environment similar to that of Earth, but also is synonymous to an ongoing threat to remove Humans and their beloved Earth from the center of life-creation.

It was long believed in ancient and medieval ages that the earth and human beings are special creation of God. Galileo and his follower Charles Darwin has broken into that house of faith with a powerful set of observations. While Galileo removed Earth from the center of the Universe, Darwin put humankind back to the nature, just another species evolved in a complex natural process.

Coming back to possibilities of life outside the Earth, one can divide the approach in two different steps. The first would be to search the Earth-like planets, in the 'Habitable zone', the next could be the search for life on the planet. Only when the step one is confirmed, people generally look into the step two.

While the existence of 'intelligent life' in our Solar system is almost (Science really cannot disprove anything) impossible, the search for the preliminary form of life is still on. The best bet on this topic is possibly Europa, the 'moon' of Jupiter. It has a hypothesized ocean beneath its icy surface, which is supposed to contain life. It also has Oxygen in its atmosphere. The same kind of life might be present in Ganymede and Callisto. Jupiter and Saturn could have been a destination of Ammonia based life as hypothesized by Carl Sagan. Besides, NASA reported strong evidence of getting life in Mars.

The extra-solar planets are still open to all kinds of life possibilities. That is why the discovery is such an important milestone in Search for Extra-Terrestrial Intelligence. However, these planets are detected via some indirect method, hence the confidence attached to the properties of the planet discovered is considered low.

On 24th this month, Scientists at the European Southern Observatory in La Silla, Chile claimed they had found the first Earth-like planet. The planet orbits within the habitable zone of Gliese 581, a red dwarf star which is a scant 20.5 light years from Earth. If oxygen or methane (tell-tale biological gases) are found in Gliese 581c's atmosphere, this would be good circumstantial evidence for life. Dr Malcolm Fridlund, a European Space Agency scientist, said the discovery of Gliese 581c was "an important step" on the road to finding life. Interestingly, Gliese 581c is so close to the Earth that if its putative inhabitants only had our level of technology, they could - just about - pick up some of our radio signals, such as the most powerful military transmitters.

One could remember the famous Franc Dreck equation to find out how difficult it could be to find an evidence of life on the Earth. It is not only extremely difficult, it costs a lot also. Due to lack of funding, a lot of projects could not take off in recent years. However, the importance of such a project can never be undermined. It would help us to identify how the life grows, or possibly what the life actually is. May be, also to create new form of life.


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