Friday, February 12, 1999 Published at 19:04 GMT
Making Mars liveable
Making Mars habitable would take centuries
Hearing how to turn Mars into a paradise for humans was just one of the reasons that thousands of astronomers attended European Astrofest 99.
The European Astrofest 99 conference and exhibition in London brought together professional and amateur astronomers. It also attracted some top scientists, like Nasa's Chris McKay.
"We think that Mars had a past with life, so that leads us to wonder if it could have a future with life," McKay told the BBC.
The first step would be to raise the temperature by adding tiny amounts of greenhouse gases to the atmosphere. Then planting plants from cold parts of the Earth would do the rest. He admitted it would take hundreds of years to complete.
Steven Young, Managing Editor of Astrofest sponsor Astronomy Today added: "There are ethical questions of should we be playing around with the environment of other planets. Friends of the Solar System, or whatever pressure groups will exist, would have something to say about it."
Comet Hale Bopp may have passed out of sight but it is still very much in mind for Dr Alan Fitzsimmons of Queens University Belfast. He explained why astronomers still very much have their eye on the comet.
This was because the heat of the sun caused the icy mass to melt and gases and dust streamed away from the core, obscuring the view.
As the comet recedes to the outer reaches of the solar system, it cools and the gases and dust dissipate. This leaves a clear view.
"The we can see how large it is and what effect travelling through the solar system had," said Dr Fitzsimmons.
Also at Astrofest 99 was Fred Espenak, Nasa's most eminent eclipse scientist. He has spent over 20 years chasing eclipses to every corner of the world.
He makes the predictions to pinpoint exactly where the eclipse track will fall and also talked about observing eclipses.