Looks like Jupiter forgot to pack sunscreen…
Hey guys, Amy here with you on DNews.
Jupiter’s Great Red Spot is arguably the gas giant’s most notable feature.
The spot is actually massive, swirling storm twice as wide as the Earth that astronomers
have been tracking since the 1800s.
And even though its shrinking to the tune of 580 miles per year — astronomers suspect
eddies feeding into the storm are affecting its internal dynamics, turning it from an
oval into a circle — it’s still going strong.
That giant storm, and the name Great Red Spot suggests, is also, well, red.
But not because Jupiter is blushing.
It’s red because Jupiter has a bit of a sun burn.
Scientists used to think that the red in the Great Red Spot was due to chemicals welling
up in the region from below the visible cloud layers.
If this were the case, the whole storm would be red, not just the top.
But new lab tests suggest something different is going on.
Jupiter’s atmosphere is composed almost entirely of hydrogen and helium with a few
traces of other gases thrown in.
Though these other gases only exist in a tiny percentage, their effects can be significant.
Two of the trace gases in Jupiter’s atmosphere are ammonia and acetylene.
In lab tests, scientists exposed these gases to ultraviolet light to simulate sunlight
interacting with these gases in Jupiter’s atmosphere.
The experiment produced a reddish material and when the team compared this material’s
spectroscopic signature to that of the Great Red Spot as observed by Cassini's Visible
and Infrared Mapping Spectrometer, they found it to be a pretty close match.
The reddish material matched a model of the Great Red Spot in which the red-colored material
is confined to the uppermost region of the giant storm.
Scientists think that below this sun-scorched redness, the storm is actually pretty bland,
colour-wise; lots of whites and grays.
But it’s not just composition of the clouds that 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 upper layers of clouds get hit with a lot
of sun light.
An interesting question now is what combinations of elements are responsible for the other
colours in Jupiter’s clouds; the planet is generally a mixed palette of oranges, browns
and reds.
But other trace gases in Jupiter’s atmosphere like ammonium hydrosulfide turned green when
exposed to UV light in a lab.
Don’t you guys think the chemistry going on in Jupiter’s clouds is just awesome?
Let us know in the comments below or you can catch me on Twitter as @astVintageSpace.
And don’t forget to subscribe for more DNews every day of the week.