We could finally see the soil of exoplanets using the sun as a telescope!

The most powerful telescope of humanity is not the James-Webb, nor the VLT in Chile. The most powerful telescope we have is also the largest star of the solar system and is housed in its center: it is the sun. Of course, it is not a tube with a mirror inside. But it acts as an amplifying lens of light.

This is the principle of a gravitational lens, like the one which allows, by chance of alignments, to see the image of a very distant galaxy greatly amplified as here For example.

A gravitational lens acts exactly like a large drop of water on a window through which you would look at an object that will appear to you enlarged and deformed. When an astronomical target is located near the limb (edge) of the sun compared to us, astronomers can take advantage of the light amplification produced by the enormous mass of the sun. Recall that our star weighs the mass of the earth 300,000 times and that this represents 99.86% of the mass of the whole solar system.

Using the sun as “enlarging”, the amplification of the signal could reach up to 100 billion, it is obviously a lot, much better than any telescope.

We could thus observe details of 1 km on the surface of Proxima of the centaur!

It is currently absolutely impossible to see the surface of exoplanets, even the closest to less than 10 light years of the earth. Recall that a light year represents almost ten billion billion kilometers! The best we can have is a luminous point in orbit around a star whose light is masked by a cache.

But with a solar gravitational microlentilla, the calculations show that for Proxima B, at 4.22 light years from us, a rocky planet located in the habitable area of ​​its red dwarf star, we could see its soil with a kilometer details. This is equivalent to satellite photos of low quality land. This would make it possible to see if water exists in the liquid state, if there are hurricanes, and even if there is life: a possible vegetation would be perfectly visible!

In 2021, a scientific study had simulated what the earth would look like photographed by a system similar to 4 light years and the result was striking, as seen in the image below.