Tau.Neutrino said:
NASA scientists want to use the Sun as a massive telescope
It’s a constant struggle to build a better telescope, and one group of scientists from NASA’s Jet Propulsion Laboratory want to use the sun to help. Specifically, they want to use the sun’s gravity as a giant magnifying glass to search for exoplanets, an idea they outlined at the Planetary Science Vision 2050 Workshop, Popular Mechanics reports.
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Huh? Can’t be done.
Let’s go back to the beginning of time, 1915 give or take a couple of years. Back then, astronomers tried to use the Sun’s gravity to observe the bending of light from distant stars. The best they could do was 50% error, because the light from the Sun is so intense that it completely masks out the light from any star near the Sun. This isn’t just a property of the Earth’s atmosphere. It’s because Sunlight doesn’t stop at the edge of the photosphere, it continues out through the corona to several solar radii.
The amount of sunlight from outside the photosphere depends on the wavelength, it’s particularly bad at X-ray wavelengths extending out many solar diameters beyond the edge of the photosphere.
The bending of light by the Sun’s gravity was finally confirmed in radio wavelengths because near solar minimum the Sun is radio quiet. That’s no help for exoplanets, though, because planets are not strong radio sources. Finally, the effect of the Sun’s gravity on the bending of light was confirmed to high accuracy using signals sent from the Cassini spacecraft. However, even there it was actually the time delay that was measurable, not the change in angle or change in brightness.
Furthermore, the Sun is in a lousy place for use as a lens, it’s too close. A gravitational lens, and more generally any lens, is most efficient when it’s half way between the observer and the object being observed. The Sun is way out of position.