First Author

When we look at the giant planets through an optical telescope, they seem to be solid masses. In fact, they feature a huge amount of movement — from winds on the surface to magnetic forces emanating from the deep interior. Moritz Heimpel, a physicist at the University of Alberta in Canada, has a long-standing interest in these planetary dynamics. On page 193, he uses a computer model to describe how the winds that form the distinctive bands on Jupiter's surface are powered by forces from within the planet. Heimpel takes time away from his modelling to explain the idea to Nature.

Why Jupiter?

I'm interested in the core of Earth and how it generates a magnetic field. We can't directly see what's going on in Earth's core, but if you look at the giant planets, such as Jupiter or Saturn, you can see the fluid dynamics occurring right on the surface. The giant planets provide a natural laboratory for the fluid dynamics of other planetary bodies.

Why this particular problem?

You can look at Jupiter with your telescope and see the bands. This model has to do with explaining how those bands come about and why they are stable.

How does this build on earlier work?

There have been previous models trying to relate how surface flow relates to the deep interior. These worked well for Jupiter's equator. What hasn't been done before is to model how the multiple high-latitude jets come about.

What was the challenge in capturing that phenomenon?

When you think about fluid dynamics on a small scale, you think about things like a creek with little whorls of current. Then you try to scale that up to planetary size. That seems like an impossible task.

How did you manage to scale the model up?

A good computing system and better code. Also, scaling theory for planetary turbulence.

What were the individual contributions from the team members?

Johannes Wicht developed the computer code. He's a physicist at the Max Planck Institute for Solar System Research in Katlenburg-Lindau, Germany. I had some ideas on how to set up the model's parameters. And I worked with Jonathan Aurnou at the University of California, Los Angeles, on scaling issues.

How do you feel about the model now?

It seems kind of nice that you can reproduce some of the main features of the planets.