Space scientists are always endeavouring to discover life around the universe in worlds beyond the Earth, but the question remains how do they attempt to determine whether life actually exists on other planets and worlds beyond Earth and just what is necessary to support life?
In 2011, scientists suggested that 50 extra-solar planets had been discovered, some of which they dubbed ‘super-Earths’ capable of supporting life. Of these ‘alien’ worlds, one struck particular interest with scientists, an extra-solar planet named HD 85512b.
Why is this planet of such interest? It’s all about location, location, location! HD 85512b is located on the edge of its parent star’s ‘habitable zone’.
So what is the ‘habitable’ zone? It is the amount of space around a star which is adequate for liquid water and life as we know it to exist on the surface of a planet in orbit of that star. This means that the temperature within that habitable zone is neither too hot, nor too cold – in fact, it is just right – hence its moniker of the ‘Goldilocks zone’. The size of this zone depends on the amount of heat – both from radiation and other sources – that the parent star emits.
Scientists on missions such as the NASA Kepler mission (which seeks life on planets around the universe) can then use these temperatures to determine whether life would be viable on a particular planet.
Naturally, life on these planets is dependent on other factors such as atmosphere, geography and mass. If a planet is too vast then life may be insupportable, if it is too small, the gravitational force needed to retain the appropriate atmosphere for life may not be attainable.
Once it is determined that a planet is habitable, it then becomes necessary to analyse the atmosphere of it to establish whether life could be plausibly sustained. At current, technology is not at the level required for this type of analysis and so it is still not known whether life exists on planets like HD 5512b and super-Earths like it.
It is possible however, to assign some indicators of life which can be measured to the pursuit of an understanding of the scope of life in the universe, such as large scale presence of oxygen. It is noted by scientists involved in missions such as Kepler, that even with such strong indicators for life, nothing should be taken for granted as natural processes can cause oxygen rich atmospheres without the gas’ actual presence.
So it seems the search for life around the universe continues but what we can take from this is that there is strong possibility that life could exist on planets beyond Earth.
Still we think we’ll hold off from booking our spaceship for a few more years…