We are used to seeing a photo of our planet from close space, where it almost always resembles a blue ball, and with proper distance, a small blue dot. But what if you try to look at the Earth from another galaxy and understand - how do the inhabitants of other planets see us? Scientists from Cornell University tried to model what our planet would look like for an astronomer of a distant civilization.
The fact is that for an observer from another galaxy, the Earth is a typical exoplanet, which scientists there, like ours, will look for by indirect signs. This means that if we understand how our world looks when viewed from the other side, we will improve our skills in finding exoplanets. And it's just curious - if aliens also use the visible part of the spectrum, how do they see our Earth?
For such a simulation, scientists took about 10, 000 images of the planet from the Cornell spacecraft located between the Earth and the Sun. The survey was carried out at different wavelengths of light waves, which were then simplified to points, and from the points they made graphs of changes in the planet's luminosity over two years. This roughly reflects what an observer sees from afar - how the luminosity of a cosmic body changes depending on the movement relative to its star, from the weather on the surface, from the change of day, etc.
The light curves were superimposed on real weather data and geographic maps, and then the computer was told to look for patterns. The result is shown in the picture - dark lines roughly reflect the boundaries of the continents, you can see the ratio of land and water on the planet. And even if the data is not very accurate, it is still progress in the study of exoplanets, an opportunity to look at distant worlds in a new way.