Georgina von Hoppe, of Corran School, asks :-

What is the most scientifically amazing thing you have come across?

Frank Andrews, an astronomer at the Carter Observatory in Wellington, responded.

Without doubt one of the most amazing things that I know of in the universe is the life which exists right here on Earth.

This now raises the question as to whether there is life anywhere else in the universe. At present scientists can't answer this question for certain but we have learnt so much about how our Sun and it's planets formed, that we know there was nothing unusual about the birth of our Solar System. When we look out into space with our giant telescopes we can see countless sun-like stars being born in exactly the same way as our Solar System came into existence some 4,600,000,000 years ago. Why should life not be possible on the planets of such stars?

What are the conditions needed for life to come into existence and flourish on a planet? A small to medium sized star with a long, stable, life. A rocky planet between 0.5 and 1.5 times the mass of the Earth. This planet must be at a distance from it's star which will allow water to exist as a liquid, because liquid water is essential to life as we know it. And the right substances to form living things have to be present.

How often might we expect to be able to meet all of these conditions in one star system? Small to medium sized stars are among the most plentiful stars in the Milky Way, so there should be plenty of suitable stars.

We do not know how many of these small to medium sized stars have planets of the right size orbiting them at the right distance. In the last two years a number of large planets have been discovered orbiting other stars. Unfortunately none of these have been earth like or suitable for life but the fact that we now know more planets outside our Solar System than in it, suggests that it won't be long before our equipment will be powerful enough to discover small-earth like worlds orbiting other sun-like stars.

Because we are able to wonder about the universe and even begin to understand a little of how it works and how we came to be here; that is why I think that life is the most wonderful thing I know of in the universe. The discovery that it is possibly quite common is the most amazing discovery of all!