Cumulative Number of Exoplanets Discoveries Versus Time

A plot showing the cumulative number of "confirmed" exoplanets discovered by year of discovery. The sample of "confirmed" exoplanets and their years of discovery were taken from the NASA Exoplanet Archive. The best fit trend to this year vs. log(N) trend is: log(N) = -262.7112 + 0.13209*(year). The slope is consistent with a doubling time of ln(2)/0.13209 = 2.28 yr = 27.3 months. Wild extrapolation of this trend suggests reaching 1 million exoplanets around 2034, 1 billion exoplanets around 2057, 300 billion around 2075 (approximately 1 exoplanet for every star in the Milky Way). A similar plot made by the author in 2008 (before the Kepler mission) showed a doubling timescale of 29 months over the period 1989-2008.