United kingdom Daily news: Planet for rent - but hurry up! Worlds may become suitable for life

Selasa, 01 Mei 2012

Planet for rent - but hurry up! Worlds may become suitable for life

Planet for rent - but hurry up! Worlds may become suitable for life

By Eddie Wrenn

PUBLISHED: 09:16 EST, 1 May 2012 | UPDATED: 09:25 EST, 1 May 2012

From what we know of the universe, the requirements for life on a planet are liquid water, an atmosphere, and a stable orbit close enough to a star to provide enough heat and warmth.

Once this narrow remit, along with a dozen other variables have been met, then life - on planet Earth at least - can flourish, and the planet becomes a habitable home.

But now researchers suggest that a planet needs the presence of life to remain habitable - and they suggest 'it is in our interest to get our heads around this soon' - especially if we wish to colonise the universe.

Homes to rent: Without complex life forms on-board, planets may not remain habitable for long

Speaking on recent discoveries, showing that rocky, Earth-like planets are abundant in the universe, Dr Charley Lineweaver, lead researcher for the Australian National University Planetary Science Institute, said: 'Determining whether these planets are habitable has become the new holy grail of astronomy.

'The new-found abundance of planets, combined with the much larger range of inhabited terrestrial environments suggests that habitable planets are common.

'This increases the probability of finding some kind of extraterrestrial life.'

But in a warning to mankind, he added: 'Habitability is not just a question of abiotic environmental conditions - the presence of life may be required to maintain the habitability of a planet over billions of years.

'Planetary habitability is a complex and confusing concept that we are only beginning to get our heads around, but as a species that wants to survive, it is in our interest to get our heads around it soon.

'Life, by managing its own environment, makes a planet habitable. It has produced adaptive features as a result of Darwinian evolution to live in colder and warmer environments

'It's kind of like an adult can live in a higher range of temperatures than a baby can.'

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Lineweaver, along with fellow researcher Aditya Chopra, said the two most important factors for life are the presence of water and a temperature range of between -20Â°C and 122Â°C.

Lineweaver said: 'Over the past few decades our exploration of the Earth has turned up life in all kinds of weird environments where we didn't think life could be in, and we're finding all types of extraterrestrial environments that we didn't know about before.

'As these two groups expand they start to overlap in big ways, and that's where habitable planets will be found.'

The two authors also speculate on the possibility of habitable planets that don't contain life. They say that the conditions for life to form are much narrower than the conditions needed for life to survive.

Lineweaver said we must hunt for planets on which humans could survive - and then set up colonies there, and compared cynics to those who criticised Christopher Columbus' proposed trip across the Atlantic Ocean.

He said: 'It's a bit like the Europeans in 1450 saying: "Hey what does it matter whether we go exploring the rest of the world?'

Lineweaver said mankind must keep studying the skies for a future home: 'The next step will be to develop a satellite that can look at the atmospheres of these planets, which will be able to give us some information about whether there is life there or not.

'And if we don't find one [a suitable planet to colonise], maybe we'll go extinct.'