Deutsche Welle:
There is a lot of information from the last six months that the Rosetta probe has been orbiting the comet. There’s been discovery after discovery. Which of those discoveries do you personally think is most astonishing?
Ralf Jaumann:
Most astonishing and most exciting are of course the dunes we see on the surface. So that’s an airless body, so no atmosphere. We don’t expect to have winds. But we see material moving across the surface.
What’s causing it?
We think that the sublimation of the icy material of the interior is causing some kind of mobility, some kind of wind on the surface that was not expected so far. So there should be a connection between the outgassing of the body, when it comes closer to the sun, and the formation of transported material on the surface. Obviously, transported material over the surface builds dunes.
We’ve always heard in the run-up to this mission – we heard about comets that we described as sort of huge, dirty ice balls. We haven’t really found water. We haven’t found ice. Why not?
Because it’s in the interior. Obviously the ice will sublime from the surface immediately. The material left on the surface is the silicatic or the rocky part of the comet. That means the surface is covered of fluffy, dirty material.
The comet is plunging down toward the sun. We’re going to be following it for about another six months. What can we expect to happen?
There are many things which we expect to happen. The first is, we will see more and more activity. We get more material coming out from the interior. And that’s not only the vapor of water ice – there must be a lot of other things coming out than this, which are carbon, which are carbon compounds, and a number of nitrogen. We probably see some kind of chemical reactions in there, and we see the body getting smaller.
The European Space Agency has a lot of different projects and missions on the books. What can we expect to see in the next months and years?
There are new missions planned on Mars. There’s a rover planned on Mars, which should drill for the first time, and get below the surface and get a sample of the subsurface, probably bringing us closer to the question whether there’s life or not. And ESA is also planning to have a mission which really can look very deep in space for extra-solar planets. Also a mission which is going back to the Jovian system, exploring the moons Ganymede and Europa, which we expect to have an ocean under their ice crust. So there’s a number of things going on with ESA.
Lots going on. Ralf Jaumann, thanks very much for joining us here on Tomorrow Today.
(Interview: Derrick Williams)