AstronomyPicture of the Day—20181123

Discover the cosmos! Each day a different image or photograph of our fascinating universe is featured, along with a brief explanation written by a professional astronomer.

2018November 23

Swirlsand Colors on Jupiter from Juno

ImageCredit: NASA, Juno, SwRI, MSSS; Processing & License: Matt Brealey, SeánDoran

Explanation:What creates the colors in Jupiter's clouds? No one is sure. The thickatmosphere of Jupiter is mostly hydrogen and helium, elements which arecolorless at the low temperatures of the Jovian cloud tops. Which traceelements provide the colors remains a topic of research, although small amountsof ammonium hydrosulfide are one leading candidate. What is clear from thefeatured color-enhanced image -- and many similar images -- is that lighterclouds are typically higher up than darker ones. Pictured, light clouds swirlaround reddish regions toward the lower right, while they appear to cover oversome darker domains on the upper right. The featured image was taken by therobotic Juno spacecraft during its 14th low pass over Jupiter earlier thisyear. Juno continues in its looping elliptical orbit, swooping near the hugeplanet every 53 days and exploring a slightly different sector each timearound.