Could We Turn the Sun Into an Extremely Powerful Telescope?

It's hypothetically capable of 'delivering an exquisite portrait of the detailed surface features of any exoplanet within 100 light-years...' writes Space.com.

'It would be better than any telescope we could possibly build in any possible future for the next few hundred years...'

While the sun may not look like a traditional lens or mirror, it has a lot of mass. And in Einstein's theory of general relativity, massive objects bend space-time around them. Any light that grazes the surface of the sun gets deflected and, instead of continuing in a straight line, heads toward a focal point, together with all the other light that grazes the sun at the same time... The 'solar gravitational lens' leads to an almost unbelievably high resolution. It's as if we had a telescope mirror the width of the entire sun. An instrument positioned at the correct focal point would be able to harness the gravitational warping of the sun's gravity to allow us to observe the distant universe with a jaw-dropping resolution of 10^-10 arcseconds. That's roughly a million times more powerful than the Event Horizon Telescope.

Of course, there are challenges with using the solar gravitational lens as a natural telescope. The focal point of all this light bending sits 542 times greater than the distance between Earth and the sun. It's 11 times the distance to Pluto, and three times the distance achieved by humanity's most far-flung spacecraft, Voyager 1, which launched in 1977. So not only would we have to send a spacecraft farther than we ever have before, but it would have to have enough fuel to stay there and move around. The images created by the solar gravitational lens would be spread out over tens of kilometers of space, so the spacecraft would have to scan the entire field to build up a complete mosaic image.

Plans to take advantage of the solar lens go back to the 1970s. Most recently, astronomers have proposed developing a fleet of small, lightweight cubesats that would deploy solar sails to accelerate them to 542 AU. Once there, they would slow down and coordinate their maneuvers, building up an image and sending the data back to Earth for processing...
The telescope already exists — we just have to get a camera in the right position.


Thanks to Tablizer (Slashdot reader #95,088) for sharing the article.

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