[X] My Assistant

[Olvegg]

New article in New Scientist

[JTN]

The PS blog reports on a report by Nelson et al at LPSC, concerning surface changes derived from VIMS measurements. This appears to be the same spot (26S 78W, just north of Hotei Arcus) as the subject of this thread.

The spectrum appears to be consistent with ammonia, and there is again speculation about cryovolcanism.

[The Messenger]

The PS blog reports on a report by Nelson et al at LPSC, concerning surface changes derived from VIMS measurements. This appears to be the same spot (26S 78W, just north of Hotei Arcus) as the subject of this thread.

The spectrum appears to be consistent with ammonia, and there is again speculation about cryovolcanism.

Only kinda, sorta:

The distortion in shape is not unexpected given that the centers of the NH3 absorption features do not exactly coincide with the centers of the methane window transparency. The spectral change we observe is inconsistent with laboratory spectra of frosts of H2O, CO2, and CH4 4 It is consistent with NH3.

In otherwords, spectral evidence eliminates H2O, CO2 and CH4 as the changing species, but does not eliminate NH3. I suspect it is also consistent with HNNH(!) and possibly HCCH. That said, there is one peak at 2.01 microns that does smell like ammonia.

Discussion: NH3 is expected to be found in Titan‘s interior.

If there is visible ammonia venting, we should find more of it in the atmosphere - even though it is destroyed by the sun, that takes time. Volcanic events, if they are venting NH3, should be beeping all the ammonia detectors.