The hunt for planets beyond our solar system has truly taken off over the last few decades, so it’s no surprise that exoplanet news has become a staple of New Atlas’ science coverage. With the recent discovery of the 5,000th exoplanet coinciding with our own 20th anniversary, now seems like the perfect time to reflect on the milestones along the way.
For as long as we’ve looked up at the night sky, it’s been assumed that there should be planets orbiting at least some of the stars we see there, but it wasn’t until 1992 that astronomers confirmed the very first detection of an “extrasolar” planet. While New Atlas (née Gizmag) wasn’t around to cover those early years of exoplanet science, we dipped our toes in the water for the first time in 2008, with the discovery of a “strikingly similar” planetary system some 5,000 light-years away.
Things really kicked off the following year, with the launch of NASA’s Kepler space telescope, which was specifically designed to search for exoplanets. Candidate detections began to pour in by the hundreds over the next few years, and by 2015 astronomers had confirmed more than 1,000 exoplanets in around 440 systems. Seven years later and that number has now swollen to over 5,000.
Some of the highlights include Gliese 581g, the first potentially habitable exoplanet; HIP 13044 b, the first candidate exoplanet found outside the Milky Way galaxy; the first detection of a rogue planet, not bound to any star; Kelt-9b, the blistering gas giant that’s hotter than most stars; Proxima b, c and d, which are the closest exoplanets to Earth at just four light-years away; and of course the TRAPPIST-1 system, which contains seven Earth-sized planets orbiting a red dwarf.
We at New Atlas have been here to cover them all – and occasionally round up some of the weirdest worlds out there, like the planet where it rains rocks, or the one that’s just a big diamond.
Here's a look at some of the biggest exoplanet discoveries over the past two decades:
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"Strikingly similar" planetary system discovered
February 20, 2008With the number of extra-solar planets so far discovered now approaching 300, astronomers have found a planetary system some 5,000 light years away that bears "striking similarities" to our Solar system. -
Kepler exoplanet tally passes 1,000
January 10, 2015NASA's Kepler space telescope's count of exoplanets has passed the magic 1,000 mark, including eight new "habitable" planets and 544 candidate planets. -
NASA confirms discovery of 5,000th exoplanet – with billions more to find
March 21, 2022The hunt for planets beyond our solar system has now reached a major milestone. A new batch of 65 exoplanets brings the total number of confirmed planets beyond our solar system to over 5,000 – with potentially hundreds of billions left to find. -
First “potentially habitable” exoplanet discovered
October 01, 2010Astronomers have discovered the first exoplanet that sits in an area where water could exist on the planet’s surface, making it the most Earth-like exoplanet yet discovered and the first strong case for a “potentially habitable” one. -
First exoplanet from beyond our galaxy discovered
November 25, 2010First extragalactic exoplanet discovered. -
First rogue planet discovered
November 15, 2012Astronomers have found what is likely to be a rogue planet that is around 100 light years from our solar system, making it the closest free-floating planetary mass yet discovered. -
Extremely uninhabitable exoplanet is hotter than a star
June 05, 2017Habitability is one of the main things we look for in exoplanets, but those that are completely and utterly uninhabitable still have plenty to teach us. NASA has just found a planet that we’re going to crown Least Likely To Host Life: KELT-9b, a blistering gas giant that’s hotter than most stars. -
Potentially habitable planet discovered just 4 light-years away
August 24, 2016A team of astronomers has discovered clear evidence of a potentially habitable Earth-sized planet orbiting the closest star to our solar system, Proxima Centauri. -
Seven Earth-sized planets found orbiting nearby red dwarf star
February 22, 2017An international team of astronomers has announced the discovery of seven Earth-sized exoplanets in orbit around a nearby ultracool red dwarf star, including three that reside in the star's habitable zone. -
Lava oceans and ruby rains: Five of the most bizarre exoplanets ever found
May 05, 2017Over the last 20 years we've discovered over 3,600 exoplanets, and some of these are far crazier than we could've imagined. Suddenly Earth seems pretty boring, so let’s take a quick tour of some of the most bizarre exoplanets that have been spotted so far. -
Kepler mission discovers first planet orbiting two stars
September 19, 2011NASA's Kepler mission has detected the first planet orbiting two stars, which broades the opportunities for life in the galaxy as most of the stars in the Milky Way are part of binary systems. -
Celebrating 20 years of exoplanet discovery
October 07, 2015This month marks the 20 year anniversary of the identification of the very first exoplanet orbiting a Sun-like star - 51 Pegasi b.