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> How big would it have to be in order to get a Google Earth resolution on a planet many light years away? If you're ok to settle for a lower resolution, then
by wcoenen 3y ago
> How big would it have to be in order to get a Google Earth resolution on a planet many light years away?
If you're ok to settle for a lower resolution, then a couple hundred astronomical units. Surprisingly, this may actually be feasible by using the sun as a gravitational lens. It would just take a lot of time to get the light collecting instrument in position at the focal point.
https://news.stanford.edu/press-releases/2022/05/02/gravity-telescope-image-exoplanets/ https://news.stanford.edu/press-releases/2022/05/02/gravity-...
Edit: the Stanford press release says that without exploiting gravitational lensing, "we would need a telescope 20 times wider than the Earth".
- intotheabyss 3y agoTo use the Sun, the focal point would have to be situated about 542 AUs. Certainly not impossible, and the resolution would be quite good, good enough to see surface details of an exoplanet.
- fortytwo79 3y agoAnd could you imagine the bokeh on a portrait?!
- fluoridation 3y ago542 AU is 0.008 LY. Not sure any planets you see there would count as exo.
- wcoenen 3y agoThat's where the focal point is, where we can capture the light, not where the exoplanets are.
- tzs 3y agoThat's one approach to use the sun as a gravitational lens for looking at exoplanets. There's another approach that instead of one big telescope sends a series of much smaller telescopes, small enough that light sails would be effective for getting them to where they need to go. Here's a PBS Space Time episode [1] that talks about this general topic, and then about the series of smaller telescopes approach. [1] https://www.youtube.com/watch?v=4d0EGIt1SPc https://www.youtube.com/watch?v=4d0EGIt1SPc