« on: Today at 00:17:58 »
Quote from: bearnard1212
other galaxies...Proxima BWe don't have telescopes with nearly enough resolution and sensitivity to study the climate of planets in other galaxies - or to detect radio/laser signs of civilisation there.
Radiotelescopes are already sensitive enough to detect radio signals from a nearby civilisation like ours (in our arm of our galaxy).
However, we don't yet have optical/Infra-red telescopes with enough sensitivity to analyse the atmosphere of planets around nearby stars (nearest 1000 or so).
- This is extremely hard to do with current telescopes (even James Webb), because any light reflected by the planet is overwhelmed by light from the nearby star.
- What is needed is a high-resolution coronagraph, which blocks out the light of the star so the light from the planet can be analysed.
- There have been proposals to build a large space-based coronagraph to find extrasolar planets and analyse their atmospheres. But it almost needs the star-blocking element to be another satellite that flies with the telescope in a parallel orbit. The trouble is, orbits are never parallel - they are always ellipses with different eccentricity and velocities. And maneuvering two satellites takes a lot of reaction mass.