James Webb Space Telescope, information, updates and discussion Options

[Quetzalcoatl]

On Europa and Enceladus, which will be studied for plume signatures, for the first of certainly more than one time, in November and December:

I'm curious about JWST's ability to identify the signature of complex organics, and how calibration work would even be performed to determine their spectra. With a somewhat unconstrained number of possible organic compounds to look for, that seems like a lot of laboratory work involving unusual conditions to develop a catalog of reference spectra. This would seem like a need that has perhaps never existed before, but will be needed for interpreting JWST spectra of many objects, including Titan, comets, nebulae, exoplanet atmospheres, protoplanetary discs, and maybe more.

One may think of Europa's and Enceladus's plumes as two more "exo"planet atmospheres for JWST to study. It's interesting to note that JWST will provide a kind of data that even missions that visit those worlds will not. Maybe we'll see the spectra published in 2023, but understanding them seems like it could be a long game.

Hey,

An excerpt from the article https://blogs.nasa.gov/webb/ , describing an observation of the Wolf-Rayet 140 binary star, or more precisely the cosmic dust shells surrounding it, might give some clues to this :

“With the Medium-Resolution Spectroscopy (MRS) mode on MIRI, we obtained the first spatially resolved mid-infrared spectra of a dust-forming WR binary in our observation of WR 140, and were able to directly probe the chemical signatures of its dust shells. Broad and prominent features in the spectral lines at 6.4 and 7.7 microns told us that the dust was composed of compounds consistent with Polycyclic Aromatic Hydrocarbons (PAHs). This carbonaceous material plays an important role in the interstellar medium and the formation of stars and planets, but its origin is a long-standing mystery. With the combined results of JWST’s MRS spectra and MIRI imaging, we now have evidence that WR binaries can be an important source of carbon-rich compounds that enrich the interstellar environment of our galaxy, and likely galaxies beyond our own.”

Of course, we have to take into consideration the big difference between plumes coming from satellites in our solar system and the dust envelopes around a binary star located at light years...

[Quetzalcoatl]

If the report that I dare to make between the observations of these two very different targets is nevertheless valid, it will not be necessary to forget the technical problem, still under investigation, for the MRS mode of MIRI.

[StargazeInWonder]

It's funny, Q, I also saw this story shortly after I posted. While it's definitely an interesting result, it is presented with qualifiers, "consistent with Polycyclic Aromatic Hydrocarbons," which indicates an educated hypothesis, but not proof, and also not very specific. I guess we're going to want to know a lot more about organics in the plumes of Europa and Enceladus, but of course, you take what you can get, and it's impressive that this sort of result can be had from light years away. We also have, in the case of Enceladus, some previous in situ sampling, and with Europa we expect that within a decade, so we will get to cross-reference one kind of data with another.

[Floyd]

Images of Pillars of Creation. Link

[Bill Harris]

That new IR view of The Pillars adds anothee dimension.

[antipode]

JWST does Titan!

Pretty impressive. Must be raining up there.

https://blogs.nasa.gov/webb/2022/12/01/webb...rns-moon-titan/

P

[Bill Harris]

Brilliant inages by Keck and Webb, note that the extreme 300km atmospheric depth is shown from surface to haze top.. And Webb clearly shows surface features.
Well done!

[Tom Tamlyn]

Some understated drama from the NASA blog post linked to by antipde:

After negotiations with the Keck staff and observers who had already been scheduled to use the telescope that evening, Imke and Katherine quickly queued up a set of observations.

Somewhat off-topic: I'm reasonably confident that a social compact exists under which scientists who agree to let their scheduled observations be bumped for urgent requests from higher profile projects get something in return, but it must be complex and fraught.

Have any authors knowledgeably explored this topic for novels of manners ... or perhaps slasher fiction? /off-topic

[HSchirmer]

Pretty impressive. Must be raining up there.

Or even weirder- hailing? (Now I'm wondering, was hail damage ever modeled for dragonfly's rotors?)

[StargazeInWonder]

Based on Cassini's monitoring, it seems that it rains on any given location on Titan only once in several decades or centuries, although when it does, the volume is extremely heavy. Despite Titan's 100% coverage in haze, the presence of clouds like these is quite rare at any given place and time. Preparing a future mission for rain seems to be like preparing a mission to Earth for hurricanes.

[StargazeInWonder]

Here are the abstracts from the JWST "First Science Results" conference held last week. These abstracts are, of course, much more broad than deep or detailed, but there's still plenty of interesting stuff here.

https://www.stsci.edu/files/live/sites/www/...-compendium.pdf

[StargazeInWonder]

Poster abstracts from the same event:

https://www.stsci.edu/files/live/sites/www/...esentations.pdf

The TRAPPIST-1 abstracts include the fact that one transit is not sufficient for detecting atmospheric molecular composition, there's some optimism that four transits may be sufficient, but also a note that features on the star TRAPPIST-1 introduced some unexpected noise that is much larger than the expected signal from a transiting planet's atmosphere. (Perhaps it is nonetheless distinguishable from atmospheric absorption features?) Again, publications from before the JWST indicate that measuring the atmospheric composition would benefit, ideally, from observations made during dozens of transits, per planet – more than is likely feasible.

[StargazeInWonder]

There's been an interruption in the function of the NIRISS instrument on the JWST. The updates have been few and probably reflect a lack of certainty on the ground. A loss of that instrument would entail a serious loss of science, but this last update makes it sound like the team is optimistic pending more information.

https://blogs.nasa.gov/webb/2023/01/24/near...rations-update/

[StargazeInWonder]

NIRISS is back online. This update doesn't say much about the cause of the glitch, but it must not have involved hardware in any serious way.

https://www.stsci.edu/contents/news/jwst/20...ence-operations

[StargazeInWonder]

NIRISS is back online. This update doesn't say much about the cause of the glitch, but it must not have involved hardware in any serious way.

https://www.stsci.edu/contents/news/jwst/20...ence-operations

EDIT:

Apparently, a galactic cosmic ray was the cause. No way to stop those, but I'm glad that they could roll with the punches.

https://www.inverse.com/science/niriss-update