The amount of available real estate in the galaxy increased dramatically this week, with the European Southern Observatory (ESO) reporting the discovery of 32 new planets outside of the Solar System.
Yes, that’s right, 32 planets. They range in size from gas giants much bigger than Jupiter, all the way down to super-Earths a few times the size of our current home world.
The announcement pushes the total number of discovered exoplanets beyond 400, a large portion of which were discovered by the folks at ESO using a handy tool they call HARPS — the High Accuracy Radial Velocity Planet Searcher, a high-resolution spectrograph attached to the organization’s 3.6-metre telescope at La Silla, Chile. This device has aided in the discovery of more than 75 exoplanets across 30 star systems since its installation in 2003.
The astronomers look for planets on stars that are similar to our Sun, as well as low-mass dwarf stars and stars with a lower metal content. Most of the planets found are gas giants, but it is the super-Earths that generate most of the excitement for the potential — however tiny — that they could harbor life. They are also commonly found in multi-planet systems, like our own Solar System.
It is worlds and the similar but still larger Neptune-sized planets that scientists place the greatest chance of life-sustaining conditions being found someday. However, so far the chemical cocktail necessary to support life has only been documented on two exoplanets, neither of them with a rocky composition believed essential to the equation. Both of these are instead “hot gas planets,” and one was also just announced this week, as Space.com and NASA each report in articles from Wednesday.
A video of the ESO announcement can be found here, complete with pretty pictures of those faraway planets — all of which are artists’ renderings, not actual images of the planets.