Most of this discovery was made by the Kepler satellite, which was ‘rendered’ recently on its TESS mission.
NASA has revealed to have registered the existence of four thousand exoplanets, resolving to publish a video where it shows these discoveries in chronological order. You can view the video in question below.
Much of the exploration was done by the Kepler Space Telescope satellite. This mission began with the launch in 2009 and brought together the equivalent of 678GB of data to date. Kepler was ‘surrendered’ last year by the Transiting Exoplanet Survey Satellite (TESS) satellite that is expected to uncover another 20,000 exoplanets in the next few years.
It remains to wait for the moment when NASA reveals the discovery of the next thousand exoplanets.