Looks like Jupiter forgot to pack sunscreenâ€¦ Hey guys, Amy here with you on DNews. Jupiter's Great Red Spot is arguably thegas giant's most notable feature. The spot is actually massive, swirling storm twiceas wide as the Earth that astronomers have been tracking since the 1800s. And even thoughits shrinking to the tune of 580 miles per year â€” astronomers suspect eddies feedinginto the storm are affecting its internal dynamics, turning it from an oval into a circleâ€” it's still going strong. That giant storm, and the name Great Red Spotsuggests, is also, well, red. But not because
Jupiter is blushing. It's red because Jupiterhas a bit of a sun burn. Scientists used to think that the red in theGreat Red Spot was due to chemicals welling up in the region from below the visible cloudlayers. If this were the case, the whole storm would be red, not just the top. But new labtests suggest something different is going on. Jupiter's atmosphere is composed almostentirely of hydrogen and helium with a few traces of other gases thrown in. Though theseother gases only exist in a tiny percentage, their effects can be significant.
Two of the trace gases in Jupiter's atmosphereare ammonia and acetylene. In lab tests, scientists exposed these gases to ultraviolet light tosimulate sunlight interacting with these gases in Jupiter's atmosphere. The experimentproduced a reddish material and when the team compared this material's spectroscopic signatureto that of the Great Red Spot as observed by Cassini's Visible and Infrared MappingSpectrometer, they found it to be a pretty close match. The reddish material matcheda model of the Great Red Spot in which the redcolored material is confined to the uppermostregion of the giant storm. Scientists think that below this sunscorchedredness, the storm is actually pretty bland,
colourwise; lots of whites and grays. But it's not just composition of the cloudsthat accounts for the reddish hue in this big storm (and elsewhere around the planet).It's the altitude of those clouds. Jupiter's uppermost cloud layer is largely ammonia,and the storm that makes up the Great Red Spot is incredibly tall meaning those upperlayers of clouds get hit with a lot of sun light. An interesting question now is what combinationsof elements are responsible for the other colours in Jupiter's clouds; the planetis generally a mixed palette of oranges, browns
and reds. But other trace gases in Jupiter'satmosphere like ammonium hydrosulfide turned green when exposed to UV light in a lab. Don't you guys think the chemistry goingon in Jupiter's clouds is just awesomeé Let us know in the comments below or you cancatch me on Twitter as @astVintageSpace. And don't forget to subscribe for more DNewsevery day of the week.