The Dog Planet

There being so much folderol over the arrival of our space probe (yes, ours… we paid for it… you and me) reaching Pluto this week, how could one possibly think of writing about anything else?  If you are a regular reader you probably sense some little bit of annoyance on my part over this enormously important event.  But before I get into the meat of editorial sophism, let’s familiarize ourselves with the facts (if such distinction may be levied on Wikipedia).

Clyde W. Tombaugh

Pluto was discovered by Clyde W. Tombaugh on 18 February 1930 while he was employed for that very purpose at the Percival Lowell observatory at Flagstaff, Az.  I would argue “found” might be a better word than “discovered” as his endeavor was based on scientific hypothesis that the recently discovered planet Neptune (planet no. 8) could not account for all perturbations of the orbit of planet Uranus (planet no. 7) and therefore suggested the existence of a planet beyond Neptune termed “Planet X” (circa 1900).  Although why it wasn’t named Planet IX I couldn’t tell you.  (If you do not understand my confusion, send me an e-mail and I will explain it to you.)  At any rate, aforementioned Tombaugh was able to capture images of a very distant wanderer that was eventually dubbed “Pluto”.

Contrary to popular belief, the planet was named after the god of the underworld from Greek mythology, not the Disney Animation Studios dog.  No, not that dog; that was Goofy who was schtoopin’ Minnie behind Mickey’s back.  If none of this commentary about dogs and mice makes any sense, e-mail me and I’ll share the source joke with you.  The name was recommended by a ten-year old girl from Oxford, England who received £5 for her trouble.

Pluto’s mean distance from the Sun is 3.67 billion miles, or 39.5 astronomical units (AU).  One AU is Earth’s mean distance from the Sun, or 93 million miles. It took nine years for New Horizons to get there.  That’s nine years paying a bunch NASA scientists to sit at monitoring consoles in case a warning buzzer indicates a problem with the space craft, or a fuse has gone bad.  The average surface temperature on Pluto is 44 Kelvin (-229^o C, -380^o F).  By contrast, Earth’s average surface temperature is a sweltering 287 Kelvin (14^o C, 57^o F).  The orbital period of Pluto is 247.68 years.  Remember, the (now classified) dwarf planet was just found eighty-five years ago.  In the time we have been aware of it, Pluto has completed only one-third of one orbit.  Thanks to Dr. Sir Isaac Newton for the tools with which we make such determinations.

Pluto has five natural satellites (or moons), but the largest (Charon) boasts a diameter just under one-half that of Pluto itself, leading many scientists to assert that Pluto-Charon is a binary system.  The same may be true of Earth-Moon, where the Moon is one-sixth the size of Earth.

Pluto

Pluto resides in the Kuiper belt which is a field of icy, rocky bodies beyond the orbit of Neptune (mostly: Pluto’s orbit, e.g., carries it inside the orbital path of Neptune during portions of its circuit around the Sun) and may mark the edge of our Solar System.  Pluto, as I’m sure you know, was originally considered a planet of our solar system.  But with the discovery of at least two larger bodies populating the Kuiper belt, Pluto has been demoted to sub-planet status.  This change in status caused no little bit of moaning and whining here on Earth back in 2006; which bring me to the point.  Who cares?

 The reported cost of the New Horizons mission is estimated to be about $700 million.   I guess that doesn’t seem like much at only a bit more than two dollars per person living in the United States.  But I think it would go a long way towards repaving the streets I drive on!