If you want to go really big, put a telescope at the focal point of Sun's gravitational lens, which is about 550 AU from it. The project is called FOCAL.
Honestly, FOCAL sounds like a not-so-great idea, even after considering my not-so-optimistic mood. But perhaps more honestly, wtf is this, where the default masses are the sun and Earth, and I can input a fucking semimajor orbital axis in units of an Angstrom, but astronomical units (AU) isn't in the selection menu? Is it a joke?! It was one of the first google results. omfg, the only thing that'd be more infuriating is if google.com's default (edit: AMERICAN) conversion factor of 1 AU was in terms of miles... @#%*&(^$ YEP, I'M IN STUPIDTOWN. THANKS FOR REMINDING ME WHY I WRITE MY OWN CODE. ANYWAY, good luck getting to 550 AU in an appreciable time. New Horizons took about a decade to get to about 30 AU, and it was the fastest object ever launched by humans (relative to the Earth), although I think maybe JUNO or the Parker Solar Probe has probably since given it at least a run for its money, if not beaten the record. Then, you've gotta make a controlled burn to linger at 550 AU for an appreciable amount of time to collect photons. Solving that issue, you get to orbit the sun incredibly slowly and map out what's behind it over the course of the next several thousand years, which amounts to only taking data within a plane, plus or minus some little bit of thickness. Obviously, there would have to be as many science targets falling within this accessible plane as was possible, and you'd have to optimize the orbit for that, but I digress. Edit 2: and yeah, good luck with filtering out the solar corona's contribution to your data via recombination and all the other interactions, cuz it's dead center of your field of view / region of interest. I'mma address some of the other things in this thread tomorrow, because, for one thing, radio waves aren't only 2 or 3 times longer wavelength than optical, but when you get a notification via 'bl00 regarding DSP and you already had this tab open in your browser for what you were up to that day, it's time for another beer
It's there, though. At the 'scientific' section, they just didn't capitalise it and it's 'au'. Absolutely true, but if goobster could brush me off on pointing out that teleporting ~10^29 particles composing the human body would be beyond stupidly difficult and doesn't-work-like-star-trek (source), I assumed that anything optimistically achievable within 100 or so years is fair game. :Pastronomical units (AU) isn't in the selection menu?
anything practical you mentioned
If you're in a position of caring what the surface of expolanets look like you'd best be in a position to get out to 550AU in an appreciable time. No, I do not have a solution in mind. Just wanted to point out that I read "550 AU" yesterday, dug 1 level deeper than Wikipedia and determined that the scientific investment and rigor behind FOCAL makes Project Orion look NASA-grade.ANYWAY, good luck getting to 550 AU in an appreciable time.