January 5: The Plutoid Planet

Eris, a dwarf planet in our solar system that is 27 percent more massive than Pluto and about a quarter the size of the Earth, was discovered on this date in 2005 by a team of three scientists that included David L. Rabinowitz of Yale University. The discovery of Eris, which has one known moon, Dysnomia, and completes an orbit around the sun every 557 years, led to the downgrading of Pluto’s status as a planet to that of a dwarf planet. Eris is often so far from the sun that its atmosphere collapses and freezes on the surface; scientists believe its surface temperatures range from minus 359 to minus 405 degrees Fahrenheit. Eris was the name of the Greek goddess of discord and strife (Discordia in Latin). Dr. Rabinowitz has also been involved in the detection of near-Earth asteroids and Kuiper Belt objects.
“A planet is a celestial body that: (a) is in orbit around the Sun, (b) has sufficient mass for its self-gravity to overcome rigid body forces so that it assumes a hydrostatic equilibrium (nearly round) shape, and (c) has cleared the neighbourhood around its orbit. A ‘dwarf planet’ is a celestial body that: (a) is in orbit around the Sun, (b) has sufficient mass for its self-gravity to overcome rigid body forces so that it assumes a hydrostatic equilibrium (nearly round) shape, (c) has not cleared the neighbourhood around its orbit, and (d) is not a satellite.” —International Astronomical Union

JEWDAYO ROCKS! Maynard Solomon, co-founder of Vanguard records, born on this date in 1930. Among the artists Solomon were the Weavers and Paul Robeson at the height of McCarthyism, as well as Joan Baez, Odetta, the Rooftop Singers, and Country Joe and the Fish.