The Closest Exoplanets to Earth
Almost all orbit around red dwarfs: stars very different from the Sun, smaller, much less bright and generally much more active than the Sun. Some of these planets are located within the habitable zone, which allows the presence of liquid water. There may even be life on some of the exoplanets in our galactic neighborhood, but it’s not easy to ascertain
To date, the existence of 4,171 exoplanets has been confirmed. As many as 3,170 were discovered by the transit method, by measuring the tiny decreases in the light flux of a series of stars, caused by the passage of a planet in front of the stellar disk, along our line of sight towards the stars observed.
But all the closest exoplanets to Earth of which official confirmation exists have been discovered by another method, that of radial velocity. This method is based on high-quality spectroscopic observations. It should be clarified that the planets are not visible in any way, as it happens, incidentally, even with the transit method. What is measured is the periodic shift towards the red or the blue of the spectral lines of light from the observed stars. This shift, due to the…
