Last Wednesday, our local astronomy club was treated to a presentation by Megan Pickett, an Associate Professor of Physics from Lawrence University in Appleton. In anticipation of NASA’s New Horizon spacecraft flyby of Pluto in less than two weeks, Pickett’s presentation was entitled “I Hate Pluto (and Why You Should, Too).”
Much of Pickett’s talk centered on the International Astronomical Union‘s (IAU) demotion of Pluto from a full-fledged planet to a dwarf planet in August of 2006. The IAU pulled Pluto’s status because of its size, its makeup, and its erratic orbit.
Because of its icy composition, Pickett said Pluto’s surface looks more like a plate of quiche than a rocky planet. She said Pluto is very small (less than 1,500 miles in diameter), and that it hasn’t cleared its orbit of debris, which is an accepted prerequisite for planet status. Additionally, Pluto’s orbit is unlike the orbit of any other planet in our Solar System.
Charon, once considered Pluto’s largest moon, is nearly the size of Pluto. It’s not even considered a moon of Pluto anymore, but rather, is classified as a binary object because the center of balance between Pluto and Charon is outside of Pluto.
Pluto is now classified as a Kuiper Belt object, one of hundreds of thousands of objects in the outer solar system. The Kuiper belt is home to the three known dwarf planets (Pluto, Makemake and Haumea) as well as most short-period comets.
On July 14, New Horizons will photograph Pluto’s surface from just 7,800 miles away. It will also survey Pluto’s moons and other Kuiper Belt objects.
Pickett has been a featured speaker for our club in the past, and always answers questions well past the museum’s closing time. She brought teammates from her other passion, the Paper Valley Roller Girls, a roller derby league she’s been president of since 2008.