WIRED @WIRED
NASA has announced a ground-breaking milestone: there are now more than 5,000 known exoplanets. "It's not just a number," says Exoplanet Archive science lead Jessie Christiansen. "I get excited about every one because we don't know anything about them." 📸: NASA/JPL-Caltech https://t.co/IbfGwDyMfA — PolitiTweet.org