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Skywatching

Not if alien life is found, but when say scientists

Searching for alien life

There has been a big change in the discussions scientists are having about life beyond the Earth. Instead of discussing whether there is life elsewhere in the universe, they are considering when we are likely to find it. In other words, we now are no longer wondering if we are alone. It is more an issue of when we will find those aliens.

At the moment we have no solid evidence of the existence of alien life out there in the cosmos, so what is it that has triggered this dramatic change?

Firstly, we now know there are other planets out there beyond the Solar System. Several thousand have been confirmed so far, with many more candidates still being checked. The James Webb Space Telescope has found giant planets in the Orion Nebula. A good number of these are likely to have water and are orbiting well-behaved stars.

Here on Earth, we find living things almost everywhere. There are insects quite happily living on glaciers. If you pick one up in your hand, the warmth will kill it. There are things living deep underground in the rocks. There are others happily swimming around in the near-boiling water in hot springs emerging in volcanic areas.

In the cold, deep, dark depths of our oceans, there are communities of bizarre creatures living around vents emitting streams of hot, mineral-laden water. Some earthly bacteria hitched a ride to the Moon on at least one of the Surveyor spacecraft, which were part of the preparations for putting humans on the Moon.

Years later, Apollo astronauts landed near one of them and removed some parts to bring home for examination. Scientists found earthly bacteria on them. They had not liked the lunar temperature extremes, the vacuum or the radiation, but they survived.

We have identified places in our Solar System where life as we know it could exist. For example, there could be living things in the deep oceans under the icy surfaces of Europa, one of Jupiter's moons, and Enceladus, one of Saturn's. These oceans are tidally heated and are likely to have volcanic vents on their floors, supporting communities of living creatures. Long ago, Mars was once like the Earth. Are there survivors eking out an existence below the surface? There are creatures here on Earth that could survive the daily temperature extremes and lack of oxygen.

Years of radio astronomical studies have shown that the dark, cold gas and dust clouds in our and other galaxies are loaded with a witches' brew of organic (carbon-based) molecules. The brew includes large amounts of the chemicals we believe to be the basis of life as we know it. Scientists are busily researching how these ingredients could have become the mixtures of amino acids and proteins powering earthly life.

Every newly born planet gets a ration of these chemicals. It is likely that a lot of them end up on planets too hostile for life to start. However, we are finding stars other than our Sun which have planets offering environments no more hostile than our boiling hot springs or freezing glaciers. So, if there is life here, why not there too?

This raises a big issue. Here on Earth, we have many examples of how, when people and other species moved to new places, it did not turn out well for the indigenous life in those places. How will we manage issues like biological contamination when we set up long-term bases, or even colonies on Mars and other worlds?

Can we responsibly exploit their resources? The Moon is probably lifeless. However we have plans to send spacecraft to Europa, where there may be living things. We will have to be very careful. Being many light years away, creatures living on planets orbiting other stars are safe from us, for now.

•••

• Saturn rises in the southeast just after sunset, with Jupiter following about an hour later.

• Venus, shining like a searchlight, rises around 3 a.m.

• The Moon will be new on Oct. 14.

Ken Tapping is an astronomer with the National Research Council's Dominion Radio Astrophysical Observatory near Penticton.

This article is written by or on behalf of an outsourced columnist and does not necessarily reflect the views of Castanet.



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About the Author

Ken Tapping is an astronomer born in the U.K. He has been with the National Research Council since 1975 and moved to the Okanagan in 1990.  

He plays guitar with a couple of local jazz bands and has written weekly astronomy articles since 1992. 

Tapping has a doctorate from the University of Utrecht in The Netherlands.

[email protected]



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The views expressed are strictly those of the author and not necessarily those of Castanet. Castanet does not warrant the contents.

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