Pondering Pluto

  Since discovered in 1930, Pluto’s status as a planet has been a point of contention.  Last week, the 424 astronomers that comprise the International Astronomical Union met in Prague to, once and for all, pinpoint the criteria for what constitutes a planet.  Pluto, unfortunately, didn’t pass the test.

  If you’re interested, the new guidelines require a planet to be round, to have “cleared the neighborhood around their [clearly defined] orbit,” and they mustn’t be satellites, that is, orbit any object other than the sun.  Pluto, which has always been the smallest of the recognized planets, is not large enough to have a clearly defined orbit, and doesn’t have the mass to create the gravitational pull necessary to “clear the neighborhood” of its orbit.  Therefore, on last week’s episode of “Planetary Survivor,” it was voted out.

  Pluto, under the new guidelines, is classified as a “dwarf planet.”  You may be thinking, “Ah ha!  So it IS still a planet!”  Wrong.  “Dwarf planet” is a new term created by the IAU to describe smaller, round bodies that orbit the sun, but “haven’t cleared the neighborhood of their orbit, and are not satellites.”  If you think that using the term “dwarf planet” to describe things that aren’t planets is confusing, you’re not alone.  Many astronomers, including the head of the IAU, have already expressed concern about the confusion the term will likely generate.

  Pluto’s demotion should be big news in Las Cruces, since its founder, Clyde Tombaugh, taught at NMSU for 18 years (1955-1973, when he retired as professor emeritus) and lived here for 42 years, until his death in 1997.  Tombaugh discovered Pluto in 1930, when he was only 24, while working at the Lowell Observatory in Flagstaff, AZ.  He helped fund, design & build the Tortugas Mountain Observatory, the little white dome that can be seen on top of “A Mountain.”  In 1990, the doors opened at Tombaugh Elementary, guaranteeing that his legend and name will be tied to the City of Crosses for years to come.

  But, as the ink dries on the resolution that downgraded Pluto, a beef is beginning to heat up in the international astronomical community.  Dr. Alan Stern of NASA has publicly criticized the IAU, of which he is not a member, calling the resolution a “farce.”  He claims that the decision is “sloppy science, and it would never pass peer review.”  “It’s impossible and contrived,” Stern says, “to put a line between dwarf planets and planets.  It’s as if we declared people not people for some arbitrary reason, like ‘they tend to live in groups’.”  Of course, Dr. Stern has a greater interest in the classification than most; he is the head of NASA’s Pluto exploration team.  He has begun circulating a petition to the 10,000 astronomers who were not a part of the IAU proceedings in an effort to have the resolution overturned.

  But Stern is probably not alone in his passion for Pluto, which may explain why CafePress.com is selling bumper stickers that read “Honk If Pluto Is Still A Planet.”  The stickers will run you $4, with all profits being donated to the Planetary Society, a nonprofit organization founded by Carl Sagan that “promotes exploration of the solar system and the search for extraterrestrial intelligence.”  Clyde Tombaugh would probably buy a bumper sticker.  Maybe you should too.

-From Pulse
   August 31, 2006