The Anatomy of Jupiter's Clouds


The great planet Jupiter reaches opposition- that time when the planet is most directly opposite the sun in the sky- on May 9, giving observers their best chance of the year to observe the features on this giant planet.  The bands on Jupiter move in different directions around the body of Jupiter.  The lighter bands move in the direction of Jupiter’s rotation, circling the planet faster than the world as a whole.  The dark colored bands move opposite the motion, taking longer to make a complete circuit.   An patient observer with exceptional optics and seeing, would see features in the dark bands fall sluggishly behind those in the light bands as the planet turns on its axis.

Data from NASA’s JUNO spacecraft has, in recent months, given new insights into Jupiter’s makeup, weather, and the motion of these bands.   By measuring the slight changes in acceleration of the JUNO satellite as it swoops a few thousand km from the Jovian cloudtops, astronomers have determined that the motion of the cloudbands we see go far deeper into the body of the planet that had been previously thought- the swirling motion goes as far  as 3000km into the body of Jupiter.  Imagine a mass of air as deep as the continental USA  is tall.

Deeper down, the mass of Jupiter moves as if it were one solid body, much like the interior of the Earth.   It is, however, anything but.  It is a great sea of hydrogen and helium so compressed that the electrons in these elements are squeezed off their nuclei- turning the body of the world into a sphere of liquid metal. 

Brad Hoehne