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I love the idea of using gravitational lensing of the sun from a lagrange point around Jupiter. IIRC it theoretically could image an earth like planet in the re

I love the idea of using gravitational lensing of the sun from a lagrange point around Jupiter. IIRC it theoretically could image an earth like planet in the region of 1000px x 1000px so you could see continents and weather systems - perhaps even light from large cities. I watched a great "Cool Worlds" video as well that said you could do similar with atmospheric lensing of the earth from a lagrange point near the moon (although it would filter out some visible light wavelengths and be weather dependant) - but potentially a much cheaper mission: https://www.youtube.com/watch?v=jgOTZe07eHA https://www.youtube.com/watch?v=jgOTZe07eHA This would be going full circle in terms of telescope technology, we started with lenses, moved to mirrors and now back to lenses! To me these seem like the most exciting missions ever - could define a new epoch for humanity and inspire and excite hundreds of millions of people. I would be very disappointed if this didn't happen in my life.

dylan604 5y ago
We went with mirrors because lenses would be astronomical in size (pun intended). So instead of having to figure out how to make an astronomical sized lens, we figured out how to use astronomical objects as lenses.
goatlover 5y ago
Seth Shostak of SETI has said that an alien civilization could setup a telescope in an orbit beyond the equivalent of Pluto, using their star's gravitational lensing to detect any Earth electronic activity up to a thousand light years away. Of course they would have to wait on our signals to reach that far out first.
zardo 5y ago
Is there some trick to make that work so close to the sun? Jupiter is 5AU out from the sun, but the solar gravitational lense focal point is 542 AU out.
jhgb 5y ago
> gravitational lensing of the sun from a lagrange point around Jupiter How exactly would that help? I thought the focal point of the Sun is around 500 AU away (i.e., not anywhere near Jupiter).
- dogma1138 5y ago
  That’s correct there was/is a suggested mission to exploit it which will require to send a telescope to 550 AUs https://en.m.wikipedia.org/wiki/FOCAL_(spacecraft) https://en.m.wikipedia.org/wiki/FOCAL_(spacecraft)

dylan604 5y ago

We went with mirrors because lenses would be astronomical in size (pun intended). So instead of having to figure out how to make an astronomical sized lens, we figured out how to use astronomical objects as lenses.

goatlover 5y ago

Seth Shostak of SETI has said that an alien civilization could setup a telescope in an orbit beyond the equivalent of Pluto, using their star's gravitational lensing to detect any Earth electronic activity up to a thousand light years away. Of course they would have to wait on our signals to reach that far out first.

zardo 5y ago

Is there some trick to make that work so close to the sun? Jupiter is 5AU out from the sun, but the solar gravitational lense focal point is 542 AU out.

jhgb 5y ago

> gravitational lensing of the sun from a lagrange point around Jupiter How exactly would that help? I thought the focal point of the Sun is around 500 AU away (i.e., not anywhere near Jupiter).

dogma1138 5y ago
That’s correct there was/is a suggested mission to exploit it which will require to send a telescope to 550 AUs https://en.m.wikipedia.org/wiki/FOCAL_(spacecraft) https://en.m.wikipedia.org/wiki/FOCAL_(spacecraft)