The Juno spacecraft should be on its way to its first close pass around Jupiter, with perigee in late August. This month Juno returned the first image from its orbit, still quite far out on it highly elliptical orbit. The JunoCam survived the initial pass around Jupiter, so we can hope to get some high resolution imagery as it swoops in.
Assuming the spacecraft and its instruments survive the stress and radiation, we sill get back some of the first detailed data about Jupiter.
This project reminds us of the awesome scale of Jupiter, which is so far beyond terrestrial scales that we have no easy intuitions about it. We can’t even really see it very clearly, due to radiation and the clouds. Juno will give us the first peak close up.
A reminder of how much we don’t know came this week with the report by James O’Donoghue an colleagues , who made careful observations from a telescope on Earth, analyzing the heat of the top of Jupiter’s atmosphere with greater resolution than ever before.
Their study sheds possible light on a long standing question about Jupiter: the outer atmosphere is much warmer, hundreds of degrees hotter, than can be accounted for. What is causing this?
The theoretical analysis is a reminder of the sheer scale of Jupiter, which is most likely heated by either gravitational or acoustic waves, most likely the latter. Essentially, the roar of all the swirling gasses is so loud that the vibration is heating the atmosphere. Wow!
O’Donoghue et al’s study offers support for this idea, because they found local heating over the Great Red Spot. This giant, long running storm appears to be making so much noise that it is heating the plasma above it, accounting for at least some of the unexplained heat. Wow!
Juno’s data should give more clues about this.
- J. O’Donoghue, L. Moore, T. S. Stallard, and H. Melin, Heating of Jupiter’s upper atmosphere above the Great Red Spot. Nature, advance online publication 07/27/online 2016. http://dx.doi.org/10.1038/nature18940