Simultaneous ground- and space-based observations in the JWST era

When used simultaneously, the benefits of ground-based telescopes (e.g., large aperture) and space-based telescopes (e.g., PSF stability) can be combined to uniquely exploit their respective capabilities. Today the largest space based aperture for an optical/infrared telescope is the 2.5 meter primary of HST; while, on the ground we have the 8-10 meter filled aperture telescopes. Will this factor of 3-4 difference continue? It seems so. When it launches in 2019 the 6.5 meter JWST will find itself, like its predecessor HST, also in the company of ground-based apertures approximately 3-4 times greater in diameter. In particular, LBT with its existing 23 meter Fizeau imaging capability, and 5 to 10 years down the road the 26-39 meter filled-aperture next generation telescopes. What does a factor of 3-4 mean in terms of angular resolution? Although an 8-10 meter ground based telescope can deliver images with a factor-of-two better resolution than HST at K-band, it becomes a wash at J-band.1 While in the visible HST stays well ahead of todays visible AO systems on ground-based telescopes. But even at longer wavelengths, where ground-based telescopes come out ahead in angular resolution, the PSF stability achieved in space trumps resolution for some programs (e.g., photometry). We will focus on a study of volcanoes on Jupiter's moon Io. Volcanoes have already been observed at the high spatial resolution achievable with a 23-meter aperture, 32 mas or 100km on Io, but unfortunately with photometric measurements which are good to only approx 10%.2 We will show how, by observing Io with LBTI Fizeau contemporaneously with JWST, the exquisite photometry delivered from space (approx. 1%) can be realized in the higher resolution, ground based observations.