More and more attention is being paid to our two ice giants – Uranus and Neptune – despite the current lack of missions being sent to the two worlds. While Venus is getting all the spacecraft love, scientists are trying to do what they can with what they have, data-wise, to understand the icy, blue worlds. And that’s incredibly difficult to do when the only spacecraft to have collected data were merely passing through the systems.

Literally on top of that issue, the ice cover on the two worlds – they aren’t called ice giants for nothing – makes it difficult to “see” the interiors of the planets. And both of these issues have led a large team of scientists to get creative, and their results can be read in a preprint on arXiv led by Joseph A’Hearn.

We’ve talked before about how a different team of scientists was working on using seismic waves in Saturn’s ring system to gain a better understanding of the gas giant’s interior. That technique could work at both Uranus and Neptune, who also have their own, smaller ring systems, but we have tons of data about Saturn’s rings from Voyager and Cassini. Honestly, Cassini in particular gathered petabytes of data on Saturn and its moons, so there is a lot of information to work with.

The method works thusly. Inside the planet, there are gravitational oscillations. One particular pattern of oscillations is known as “normal mode”, and that pattern occurs when every part of the planetary system begins to oscillate at the same frequency. The effects of the wave can be felt throughout the entire planetary system, including within the rings. And those effects can then be measured and mapped to the interior of the planet.

As we mentioned before, this technique has successfully been used on Saturn’s rings.

And then there are moons that are shepherding the rings. This occurs in both Saturn’s rings and in the rings of Uranus and Neptune. Those moons will also move at the same resonance and can even create their own that will show effects in the rings. But we need more data.

Hey, NASA! We really need an ice giant orbiter or two.

More Information

The Rings of Uranus and Neptune Could Help Map Their Interiors (Universe Today)

“Ring Seismology of the Ice Giants Uranus and Neptune,” Joseph A. A’Hearn et al., accepted to The Planetary Science Journal (preprint)