‘Earth-like planets are going to be quite common’

Now we’re ready to do some science! Kepler’s mission is to detect planets outside our solar system that roughly have the same size,conditions and distance from their stars as Earth. Kepler is likely to send us evidence of hundreds of Earth-like planets revolving around hundreds of Sun-like stars.

You are a big believer in “we are not alone.” Why?

From ground-based observations,we know that Earth-like planets are going to be quite common. Estimates are that “earths” probably occur in 10 to 20 per cent of the stars. My feeling is that if you have that many earths and you have some prebiotic soup,comets that bring in the organic chemicals that you need to have life,something is going to grow. You might not always end up with dinosaurs and cavemen,but there are going to be planets out there that will have primitive life. Life on Earth is so vigorous and so able to thrive and fill every niche,how could it not be elsewhere?

So you are not an Earth chauvinist?

Few astronomers are. We understand that we’re just a speck of dust in our galaxy in the midst of an incredible universe. As far as we know,the laws of physics work the same everywhere and produce the same conditions. There’s a good chance that a large fraction of stars will have habitable planets. If you throw the dart,you’re sure to hit something.

Do you think it’s possible that other life forms from elsewhere could detect Earth’s civilisation?

The military radar leaving our planet is probably the strongest signal from our planet. If others are looking for us,they could pick up the radar. In fact,there’s an active argument within the extraterrestrial intelligence community as to whether we should be announcing that we’re here,instead of just listening quietly. Some people think we should stay quiet.

What do you think?

That’s kind of silly. The speed of light is so fast and distances are so immense between stars that there’s zero probability that anybody could come here to invade. Travelling between stars is pretty much the territory of science fiction. With our current best rockets,it would take us 1,00,000 years to reach the closest star. I wouldn’t worry about the interstellar air-raid sirens going off tonight.

I understand you have an asteroid named for you. What’s that like?

It’s not as splendid as one might think. There are something like 4,00,000 known asteroids,including,Alanboss,Minor Planet,No. 29137. I believe that Eugene and Carolyn Shoemaker found it,and for some reason named it after me. I guess because I was known for work on planet and star formation and they ran out of people to name things after. I’ve never even seen a picture of my asteroid.

Boss’s new book,The Crowded Universe: the Search for Living Planets,is about the scientific hunt for extraterrestrial life