Summary:
- This article discusses the discovery of a large number of "alien Earths" or exoplanets that closely resemble our own planet Earth. These exoplanets were detected using a technique called "transit photometry" which measures the dip in a star's brightness when a planet passes in front of it.
- The article explains that the Kepler Space Telescope, launched in 2009, has been a key tool in finding these exoplanets, detecting thousands of them orbiting other stars. This has revealed that Earth-sized planets are common in our galaxy.
- The article also mentions that future missions and telescopes, such as the James Webb Space Telescope, will allow scientists to study the atmospheres of these exoplanets and search for signs of potential habitability or even life.