It seems crazy now, but it wasn't long ago we had no hard evidence of planets existing outside our solar system. Known as "exoplanets," the first definitive discovery of one didn't come until 1992. For many years after that, a trickle of distant worlds were added to the known exoplanet catalog.
Only in the last decade, with the help of the, has the pace of discovery really increased exponentially. In June, the 4,000th exoplanet was confirmed.
That's a big leap in a single lifetime, and to mark just how far we've come in refining our view of the universe, NASA shared the above video visualization created with its data by science outreach project System Sounds. It shows when and where in the night sky all the known exoplanets were discovered. Note how quickly the pace of the finds picks up once Kepler starts making its contribution in 2010.
Kepler went to sleep permanently in 2018, but its legacy has been picked up by other observatories like the, which has already found over 700 new planet candidates in its first year in space.
Next up, the European Characterizing Exoplanets Satellite (CHEOPS) is set to launch by the end of the year andis set to blast off in 2021. Both space telescopes will be able to do more than just spot exoplanets -- they could help determine if conditions exist to support life upon their surfaces.
Originally published July 10, 12 p.m. PT.