See more
… planet. Left undecided was what to do about all the so-called planets being discovered outside the solar system, a number that now approaches 5,000.
…tional Astronomical Union established new criteria for determining what classifies as a “planet,” a controversial move that officially (but not in spirit) stripped Pluto’s status as the solar system’s ninth planet…
Nine years ago, the International Astronomical Union established new criteria for determining what classifies as a “planet,” a controversial move that officially (but not in spirit) stripped Pluto’s status as …