Date: August 29th, 2012

Title: What in Tarnation Is a Kuiper Belt Object?

Podcaster: Hoss von Liederhosen

Links: Original music is at: http://www.acidplanet.com/artist.asp?songs=645148&T=3156

Description: We had ourselves a fairly orderly Solar System up to the orbit of Neptune. The discovery of a multitude of icy moonlets beyond the orbit of Neptune made a mess of it all.

Bio: Hoss von Liederhosen has no scientific or astronomical credentials whatsoever, merely a fan of things going on beyond Earth’s atmosphere and mankind’s investigation of them. He also has some radio theatre and music background.

Today’s Sponsor: This episode of 365 days of Astronomy is sponsored by iTelescope.net – Expanding your horizons in astronomy today. The premier on-demand telescope network, at dark sky sites in Spain, New Mexico and Siding Spring, Australia.

Transcript:

ANNOUNCER: For 365 Days of Astronomy, this is Hoss von Liederhosen.
Today’s episode: (echo) Kuiper Belt Objects. Perhaps some of you are asking,

CRANKY OLD MAN:  Now what in tarnation is a Kuiper Belt Object?

ANNOUNCER:  We need a little background here. In fact, let’s take it ALLLL the way back.

ANNOUNCER:  In the beginning, early man noticed that…

(Crickets, exotic birds)

CAVEMAN: Uggh! Sun go away, lots of little lights, in sky, at dark. Uggh! They stay, same place, every dark. Uggh! Four lights, in sky, are travelers! Uggh! They move slow, over several moons, to new places, with other lights. Uggh!

ANNOUNCER: Early man knew our solar system well enough that he could identify Venus, Mars, Jupiter and Saturn, but wasn’t sure what they truly were. The planet Mercury can only be seen in the sky a few days a year, but we figured that one out too. Now let’s move ahead to…

TOP-40 DEEJAY: Solid gold, from that fabulous year, 1929.

CRANKY OLD MAN: We had ourselves eight planets, and we LIKED it that way! They used their newfangled telescopes to find Uranus in 1781 and Neptune in 1846. And they all rotate around the Sun in a similar ecliptic plane as Earth at different distances. I like my Solar Systems to be simple and orderly. But ya know what I don’t like? A bunch of junk! They call ’em Asteroids, I call ’em a bunch of junk! There should be one nice big fat planet in the space in between Mars and Jupiter. Instead there’s thousands of rocks, ahhh, one of them’s the size of Texas, the rest of ‘em are a bunch of junk!

ANNOUNCER: Then, in 1930, frankly, it all went to Hell. Astronomer Clyde Tombaugh discovered Pluto, named for the Roman God of the Underworld. The ninth (gulp!) planet. A new discovery should increase our knowledge, but Pluto seemed to pose more questions than give answers. That lovely ecliptic plane where most planets orbit within 3 degrees of each other? Pluto is 17 degrees out of whack. All planets’ orbits are slightly elliptical, even the Earth’s. Pluto’s orbit is 14 times more “out of round” than is Earth’s. Going away from the Sun, the planets Jupiter, Saturn, Uranus and Neptune all taper down in size gradually, but Pluto is a mere grain of sand by comparison. Was this really the ninth (gulp!) planet? Along came the 1940’s, and new Solar System theories emerged. In 1943, astronomer Kenneth Edgeworth published a paper theorizing the remaining mass of the Solar System should not have enough gravity to absorb all other bits of rock and ice, or “planetessimals” within any one orbital path, and comets and asteroids could exist outside the orbit of Neptune. In 1950 Jan Oort theorized that the population of comets aren’t just the ones which happen to zip by the Earth, there may be trillions of them in the vast reaches between our Solar System and the beginning of interstellar space, forming a cloud encircling the Sun. In 1951 Gerard Kuiper proposed that a ring of icy moonlets could exist beyond the orbit of Neptune.

CRANKY OLD MAN: Dagg nabbitt, he was right!

ANNOUNCER: This area was later named the Kuiper Belt, and in 1992, astronomers David Jewett and Jane Luu found the first Kuiper Belt Object, also known as a Transneptunian Object. The distance between the Earth and the Sun, 93 million miles, is called 1 Astronomical Unit, or AU. Neptune orbits around 30AU. Jewett and Luu figured out that the first Kuiper Belt Object 1992QB1 orbits around 42AU from the Sun. The Kuiper Belt is said to extend from 30AU to 55AU. As of April 2012, we have identified and plotted the orbit of over 1,300 Kuiper Belt Objects, with new discoveries every day. Several of the larger KBO’s have one or more moons. In 2002, the first big Kuiper Belt Object named Quaoar was discovered, at over 500 miles in diameter. 2004 brought with it the discovery of the object Sedna, currently the most amazing object in the Solar System. The outer limit of the Kuiper Belt is 55 Astronomical Units, right? Sedna, named for the Inuit goddess at the bottom of the frigid ocean, moves in an elliptical orbit whose closest distance to the Sun is 76AU and furthest distance is almost 1,000AU from the Sun.

TOMMY CHONG: (60’s music) Wow man, that’s like really far out!

ANNOUNCER: Sedna is roughly one-third the size of Pluto, and it ventures out into the region where Jan Oort had his cloud of comets encircling the Sun, the Oort Cloud. It takes over 10,000 years for Sedna to make one orbit of the Sun.

CRANKY OLD MAN: Kids these days! Have some patience!

ANNOUNCER: In 2005 we had a real mess on our hands. An object, a near perfect twin in size to Pluto, was discovered in the Kuiper Belt, and was named after Eris, the Roman goddess of chaos and discord. Was this the tenth (gulp!) planet? Now that astronomers have found hundreds of icy bodies near the orbit of Pluto, astronomers began to evaluate “What is a planet?” Today, Pluto is not considered a planet because it does not have enough mass and gravity to clean out all the smaller bits of rock and ice in its orbit, and Pluto orbits in the same general area as 1,300 other Kuiper Belt Objects. So what do we do with Pluto? We now have a new category of celestial body: Pluto is a dwarf planet, or minor planet. It has enough mass and gravity to form itself into a near perfect sphere, but not enough to clean out its orbit. Its twin Eris is extremely bright and reflective, perhaps venting ice crystals, and is far denser, perhaps rockier than icy Pluto. Other dwarf planets in the Kuiper Belt include Makemake, and Haumea, which spins so fast that its spherical shape has morphed into a rugby ball. These four dwarf planets join Ceres in the Main Asteroid Belt between Mars and Juipter, making 5 dwarf planets in 2012. In 2009, astronomers using the Hubble Space Telescope found an Kuiper Belt Object only 3/5 of a mile across at 45 times the Earth/Sun distance. Currently, the New Horizons spacecraft is on course for Pluto and its system of five moons, after studying the granddaddy of Kuiper Belt Objects, it will continue on through the Kuiper Belt. At the moment, its trajectory is not taking it near any known Kuiper Belt Objects, but that all could change as we discover more of these icy bodies. The study of KBO’s may answer riddles about the Inner Solar System.

1920’s VOICE: Why does Saturn’s moon Phoebe have such an unusual orbit?

SEWER EFFECT: Is it a captured Kuiper Belt Object?

1920’s VOICE: Why is Uranus rotating on its side?

SEWER EFFECT: Did it collide with a Kuiper Belt Object?

1920’s VOICE: Why does Neptune’s large moon Triton orbit the planet in the opposite direction of all other moons?

SEWER EFFECT: Is it a captured Kuiper Belt Object?

ANNOUNCER: A paleontologist studies ancient life by looking at old bones. Kuiper Belt Objects could be the “old bones” of the formation of the Solar System. For 365 Days of Astronomy, this is Hoss von Liederhosen.

End of podcast:

365 Days of Astronomy
=====================
The 365 Days of Astronomy Podcast is produced by the New Media Working Group of the International Year of Astronomy 2009. Audio post-production by Preston Gibson. Bandwidth donated by libsyn.com and wizzard media. Web design by Clockwork Active Media Systems. You may reproduce and distribute this audio for non-commercial purposes. Please consider supporting the podcast with a few dollars (or Euros!). Visit us on the web at 365DaysOfAstronomy.org or email us at info@365DaysOfAstronomy.org. Until tomorrow…goodbye.