How many planets outside our solar system, known as exoplanets, exist throughout the Milky Way Galaxy? While that might never be determined, NASA recently announced the total number of confirmed exoplanets has reached a historic 6,000, with an additional 8,000 exoplanet candidates still being analyzed for confirmation. This milestone underscores the tireless and dedicated efforts of thousands of scientists and engineers worldwide who strive to improve our understanding of our place in the universe and what might exist beyond Earth.
While the first confirmed exoplanet was officially announced in 1992, it wasn’t until 2015 that the 1,000th exoplanet was confirmed, but it was only another 7 years to hit 5,000. This increased rate of discovery and confirmation is a testament to the incredible technological achievements that have occurred in that time, most notable NASA’s Kepler Space Telescope.
“Each of the different types of planets we discover gives us information about the conditions under which planets can form and, ultimately, how common planets like Earth might be, and where we should be looking for them,” said Dr. Dawn Gelino, who is Manager of NASA’s Exoplanet Exploration Program (ExEP). “If we want to find out if we’re alone in the universe, all of this knowledge is essential.”
One of the most astonishing aspects of confirming so many exoplanets is the discovery that other solar systems aren’t like our own, which has rocky planets orbiting closer to the Sun and gas giants orbiting farther out. There are hundreds of exoplanetary systems that exhibit completely opposite architectures, specifically with gas giants orbiting extremely close to their stars.
Examples of key exoplanet discoveries that have been made include Proxima b, which is the closest confirmed exoplanet to Earth and a rocky world located 4.24 light-years from Earth while orbiting in its star’s habitable zone. One of the most incredible discoveries was the TRAPPIST-1 system, which is located approximately 40 light-years from Earth and boasts seven potentially rocky worlds, three of which orbit within the habitable zone.
How soon until NASA confirms its 7,000th exoplanets? Only time will tell, and this is why we science!
As always, keep doing science & keep looking up!
Sources: NASA JPL, NASA, Wikipedia
Featured Image: Credit: NASA’s Goddard Space Flight Center