Since 2009, the Kepler Space Telescope, which uses the transit method to discover planets (3924 exoplanets found), along with other methods like gravitational microlensing (141 exoplanets found), radial velocity (1018 exoplanets found), and direct imaging (61 exoplanets found) have aided in the discovery of over 5,000 exoplanets! We didn't even know other planets existed outside of our solar system until 1992, only 3 decades ago, and now, in less than half a lifetime, we’ve found thousands of planets ranging in sizes, orbits, and composition. Everywhere we’ve looked for planets, we’ve found them, and we're only just getting started. We’ve only searched about 1/1 millionth (.000075% of stars) of our own galaxy and there are TRILLIONS of galaxies. When it comes to exoplanet types and composition, there’s a variety of planets: 30% are gas giants like Jupiter and Saturn. 35% are Neptune like. 4% are small rocky planets like Earth, Mars, Mercury, and Venus. And finally, 31% are super earths, sometimes referred to as mini Neptunes. Some of these planets may be rocky worlds, water worlds, or earth like planets that are covered in a thick, gaseous atmosphere, which we’ll explore momentarily. What makes exoplanets great candidates for life? Geologically active, thick atmosphere, approx. 80 degrees Fahrenheit, scattered islands with shallow water, orbiting a longer living star. Types of stars and their habitability: O, B, A, F, G, K, M Super-earth exoplanets of interest: Kepler-22b Gliese 667 Cc Kepler 69c Kepler-442B Kepler-62f Kepler-186f Kepler 1229b Kepler 1410b Kepler 560b Kepler 438b Kepler 296e Earth sized exoplanets of interest: Proxima Centauri B Ross 128b Teegarden’s star b TRAPPIST system TRAPPIST-1e TOI 700d Luyten b Wolf 1061c Should we colonize super earths? What’s next in the search for ET? Credits: NASA/JPL/ESO/ESA https://www.liebertpub.com/doi/pdf/10.1089/ast.2019.2161 https://iopscience.iop.org/article/10.3847/1538-4357/abfd9c https://aasnova.org/2020/09/29/life-finds-a-way-even-on-m-dwarfs/ By Rursus - Own work, CC BY-SA 3.0, https://commons.wikimedia.org/w/index.php?curid=3015833