It sounds crazy now, but it was not so long ago, we had no tangible proof of the existence of planets outside our solar system. Known as "exoplanets", the first definitive discovery did not take place until 1992. For many years after that, a net of distant worlds was added to the catalog of exoplanets known.
In the last decade alone, with the help ofhas the pace of discovery really increased exponentially? In June, the 4000th exoplanet was confirmed.
It's a big leap in a lifetime and to mark how far we've managed to refine our vision of the universe, NASA created the video above, showing where and when all the known exoplanets were discovered in the night sky. Note how fast the pace of discovery accelerates when Kepler begins contributing in 2010.
Kepler fell asleep permanently in 2018, but his legacy was taken up by other observatories like, which has already found more than 700 new candidates on the planet in its first year in space.
Then, the European Exoplanet Characterization Satellite (CHEOPS) should be launched by the end of the year andshould take off in 2021. The two space telescopes will be able to do more than just locate exoplanets. They could also help determine if there are conditions conducive to life on their surfaces.