Lens named Sun: how to get exoplanet photo
If you organize a competition for the most popular field of science among the general public, then astronomy will surely be in the top three winners - more precisely, that part of it that is engaged in the search for life outside the Earth. This topic has become especially fashionable since the mid-1990s, when astronomers found methods to search for planets from distant stars, estimate their mass, distance to their stars, and even get information about the composition of their atmospheres.
Better to see once
Today, there are thousands of open exoplanets; The public’s love for news about them, and especially about potentially inhabited planets, made it possible to find funds for the construction of specialized tools, such as the Kepler and Gaia space observatories, and to allocate months of observational time for ground-based telescopes to search for exoplanets. We already know a lot about open exoplanets, we can estimate the temperature of water on their surface and the amount of oxygen in the atmosphere. But none of the living people have ever seen exoplanets the way we saw the planets of the solar system - in photographs where you can see the details of the relief or, for example, clouds. Most exoplanets are detected by indirect methods - measuring the speed of stars, fluctuations in their brightness and deviations of the orbits. Only very few of the planets can be directly observed - those that are relatively close. They can even be photographed, but the quality of such images is lower than that of the first black hole that caused the noise. As a rule, planets look like several bright pixels on them.
However, it is theoretically possible to get clear photos of the planets from other stars, and a group of scientists from the Jet Propulsion Laboratory (JPL) proposed such a project. Now SGLP (Solar Gravity Lens Project) is engaged in JPL and non-profit organization Aerospace. The idea is to use the Sun as a gravitational lens and through it get a hundred billion times magnified images of planets that revolve around alien stars.
According to preliminary calculations, even a small telescope with a mirror a meter in diameter and a modest coronograph (a device that allows you to block the light of the Sun), placed in the focus of the solar graviline lens, will give an image of an exoplanet removed one hundred light-years away, such that every pixel will correspond to the kilometer of the surface of the exoplanet. In order to shoot a similar image without a solar lens, you would need a telescope with a mirror with a diameter of about 80 km.
Einstein's ring is a small area of space on the focal line of a gravitational lens in which photons emitted by an observable body converge">