Neptune and Uranus are thought to be the dullest planets in the solar system. Why did you pick such uncharismatic bodies to study?
They are not dull. They change a lot. But yes, they are the Rodney Dangerfield of the solar system—they don’t get respect. They are called the Icy Giants. They’ve been less studied than nearer planets. So whenever I make an observation, anything I find is brand new. With Uranus, now we’re rewriting the textbooks on it. Uranus’s atmosphere is turning on, bright clouds, great dark spots, all sorts of convective activity, which 20 years ago we didn’t see.

Though it’s not your planet, have you been following the recent news from Mars?
Yes. And it’s very exciting. The soil is good. There’s ice. There may be places where the ice is more accessible. It means that there aren’t physical reasons to stop us from colonising that place, if that’s what the fate of humanity is going to be.

Are we getting any closer to discovering possible life outside the solar system?
That’s become a fun question now that we’re discovering planets around other stars. Over 300 new extra-solar planets have been found. The first step is to locate an Earth-size planet the right distance from its own star for water to have been in liquid form long enough to allow life, as we know it, to develop. Then we will have to look at the chemistry of its atmosphere and look for signs that it has been modified by the presence of life. That will be the clue.
_CLAUDIA DREIFUS, NYT