Astronomers Probe Mysterious Gas In Titan's Atmosphere 104
sciencehabit writes "A fluorescent glow high in the atmosphere of Titan, Saturn's largest moon, signifies the presence of a gas that astronomers have yet to identify. The glow appears only on the daytime side of the moon at altitudes between 600 and 1250 kilometers, with the largest intensity occurring at an altitude of about 950 km. Detailed analyses reveal that the glow doesn't stem from a problem with the Saturn-orbiting Cassini craft, and it isn't associated with methane or any of the other hydrocarbons already identified as constituents of Titan's atmosphere."
Re:Is it sentient? (Score:5, Informative)
we've found silicon based flora in our own deep oceans
Citation needed. There are no silicon-based life forms known to man.
Re:No spectrograph? (Score:5, Informative)
RTFA.
Of course it does. That's how they know it's there. They're just not sure what is making it... maybe aromatics.
Re:No spectrograph? (Score:5, Informative)
According to TFA, it does, but the spectrum is very near to methane, which is making it hard to identify this other gas.
fluorescent organic molecules? (Score:5, Informative)
*groan over the uranus, fartgas, and other dumb jokes.*
Anyway, since this is occuring over the sunlit side of the moon, and that the moon is very far away from the sun, and that solar wind particle action on the moon's atmosphere would be shockingly small, (Saturn's magnetic field would push a good deal away, and even then the distance means a radically lower conentration than we are used to dealing with, meaning solar ions are unlikely as a cause.) Is it possible that there are tiny organic molecules up there with a fluorescent property?
Titan has lots of methane, nitrogen, and ambient radiation from Saturn. Tiny particles just a few molecules in size suspended in the upper atmosphere would be all that's needed. Essentially, glow in the dark organic dust?
It would be interesting to see if there are other re-emission falloff zones in that part of the atmosphere relating to the e-ring charge emissions from Saturn, and other nearby energy sources that could excite a light emitting molecule.
Re:fluorescent organic molecules? (Score:4, Informative)
That seems likely- data from other instruments on Cassini [acs.org] has suggested that aromatic hydrocarbons such as benzene and anthracene form high in Titan's atmosphere. The altitude (~1000km) is consistent with the location of the glow, and the emission line fits- a mix of polycyclic aromatic hydrocarbons has long been thought to be the source of a 3.3 micron emission line seen in interstellar dust. [nasa.gov]