Sunday, 5 June 2016

Sneak peek into Jupiter

‘We use Earth-bound radio observations to peer beneath Jupiter’s surface.’ says Imke de Pater in this week’s issue of Science. With radio waves, she and her team managed to see what goes on under Jupiter’s surface.

Mixed signals
An ammonia molecule
The scientists were able to see as deep as a hundred kilometres beneath the surface. They have discovered lots of ammonia. The ammonia has confused scientists for quite a while. When spacecraft Galileo dropped a probe into Jupiter’s clouds in 1995, the probe already discovered really high concentrations of ammonia. This was quite strange, since the VLA radio telescope in New Mexico never managed to find such high concentrations of ammonia. This made scientists think that Jupiter’s atmosphere must consist of two layers; one with high concentrations of ammonia, and one with low. That were sometimes mixed up a bit by thunderstorms. Recent studies with an improved version of the VLA radio telescope show that there’s no need for two layers in the atmosphere, and that Galileo’s space probe just dived into a strange part of the atmosphere.

The radio wave picture (top one) shows
 the movements of ammonia in Jupiter’s atmosphere, 
the bottom picture is a normal picture taken by Hubble.
Simplifying the stripes
The new version of the VLA radio telescope has discovered stripes in Jupiter’s atmosphere, close to its equator. These stripes have alternating high and low concentrations of ammonia. And the high concentrations are caused by plumes of ammonia that rise from deeper inside Jupiter. This discovery enabled Imke de Pater and her team to fit both the high and low concentrations of ammonia into the same pattern. This pattern gives us a more detailed understanding of what’s going on around a hundred kilometres deep in Jupiter’s atmosphere. And also of the processes that happen much deeper in the atmosphere, since the patterns higher up are influenced by the processes lower in the atmosphere. Like when you see the fiftieth domino in a line of dominoes fall, you know that the first one also has fallen.

Husband and wife
This knowledge is also helpful for a new mission to Jupiter. Next month, space probe Juno is going to arrive by Jupiter. It is going to orbit around Jupiter and researching its gravity field, magnetic field and also concentrations of water and ammonia. With researching the water concentrations on Jupiter, scientist hope to find out more about Jupiter’s origin. And the new explanation of ammonia concentrations can be tested by Juno. This space probe can also peek deeper into Jupiter, because it’s way closer.

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