Post by Chicago Astronomer - Astro Joe on Jan 11, 2006 18:29:13 GMT -6
Kuiper Belt Moons Are Starting to Seem Typical
In the not-too-distant past, the planet Pluto was thought to be an odd bird in the outer reaches of the solar system because it has a moon, Charon, that was formed much like Earth's own moon was formed. But Pluto is getting a lot of company these days. Of the four largest objects in the Kuiper belt, three have one or more moons.
"We're now beginning to realize that Pluto is one of a small family of similar objects, nearly all of which have moons in orbit around them," says Antonin Bouchez, a California Institute of Technology astronomer. Bouchez discussed his work on the Kuiper belt Tuesday, January 10, at the winter meeting of the American Astronomical Society (AAS).
As for the other Kuiper belt objects, experts at first thought that the bodies acquired their moons only occasionally by snagging them through gravitational capture. For the smaller bodies, the 11 percent figure would be about right.
But the bigger bodies are another story. The biggest of all-and still awaiting designation as the tenth planet-is currently nicknamed "Xena." Discovered by Caltech's Professor of Planetary Science Mike Brown and his associates, Chad Trujillo of the Gemini Observatory and David Rabinowitz of Yale University, Xena is 25 percent larger than Pluto and is known to have at least one moon.
The second-largest Kuiper belt object is Pluto, which has three moons and counting. The third-largest is nicknamed "Santa" because of the time of its discovery by the Mike Brown team, and is known to have two moons.
"Santa is an odd one," says Bouchez. "You normally would expect moons to form in the same plane because they would have accreted from a disk of material in orbit around the main body.
"But Santa's moons are 40 degrees apart. We can't explain it yet."
The fourth-largest Kuiper belt object is nicknamed "Easterbunny"-again, because of the time the Brown team discovered it-and is not yet known to have a moon. But in April, Bouchez and Brown will again be looking at Easterbunny with the adaptive-optics rig on one of the 10-meter Keck telescopes, and a moon might very well turn up.
More here: www.physorg.com/news9796.html
=========
It must be troubling to the steadfast mainstream conformist in that their view of cosmology is changing daily.
It's a different Universe today, I'm glad...