planet nine

  • A 1980s Space Telescope May Have Seen Planet Nine

    A 1980s Space Telescope May Have Seen Planet Nine

    In 1983, astronomer Michael Rowan-Robinson conducted a search for a proposed 10th planet (Pluto still being a planet at the time) using data from the Infrared Astronomical Satellite, the first infrared space telescope. Rowan-Robinson didn’t turn up a new planet, and by 1991, he was pretty sure that such a planet did not exist, at…