Jupiter System L1 Observatory Options

[JRehling]

An interesting new-to-me proposal is for a space observatory that would observe the Jupiter system for years from the L1 position – sort of a hybrid between a (Earth orbiting) space telescope and a planetary orbiter. This would be "outside" the Jupiter system, but about 15 times closer to it than a mission like HST, observing it from Earth orbit.

It's one of several solar system space telescope missions outlined here.

https://www.lpi.usra.edu/opag/meetings/opag...yanagi_6012.pdf

Roughly speaking, a 50-cm telescope at Jupiter's L1 would provide imagery about 3 times sharper than HST. I imagine that the operations would consist primarily of continuous observations of Jupiter, Io, and Europa. Jupiter and Io, obviously, provide known, constant variation in activity. Europa's plumes would be another phenomenon to monitor if possible. Ganymede and Callisto less obviously provide dynamic phenomena to monitor, but would merit enough observations to determine what can be seen, including aurora. Finally, a telescope located there would provide some opportunistic imaging of the outer satellites. In favorable circumstances, an outer satellite might be located about three times closer to this telescope than Jupiter itself is, providing about 10x the resolving power of HST. That would allow for the imaging of detail on the larger ones.

[stevesliva]

Thanks for starting the thread on this. I agree that Jupiter L1 is an interesting idea. To say nothing of the satellite monitoring, think of the movies of the atmosphere, aurora, comet impacts... And '50cm' is not a size pulled out of thin air-- it's the aperture of HiRISE, on MRO.

I have to say, though, that 50cm seems small enough that even at conjunction, Saturn/Titan is probably too far away. So basically just Jupiter.

*I* did not start this thread because the slides on the telescopes larger than the Webb telescope / gap in UV coverage made my head hurt. Big problem, $$$ solutions. Makes me wonder if some of the UV sensors pointed at the Sun can be adapted.

[JRehling]

For the obligatory "but what else?" question, I think a Jupiter L1 observatory might provide rare opportunistic data in terms of photometry of mid-solar system objects (I'm thinking primarily comets, maybe asteroids, and also interstellar objects) so that light curves from Earth and from near Jupiter could be combined to produce better shape models and/or understanding of comet outbursts. But otherwise, this would really be just a Jupiter-system observatory. For Saturn it would certain provide fine observations every 20 years, but that doesn't seem like a significant value.

Yes, the article also discusses big general purpose or solar system space telescopes to succeed HST/JWST. I think the emphasis on UV includes all three of these: the ability to get the finest possible resolution (short wavelength), a point of contrast from JWST's IR spectral range, and of course, those phenomena like airglow which are particularly bright in UV.