Tuesday, October 11, 2005
Wanderers
DarwinCatholic blogged last Friday about moving planets. We get the word, by the way, from the Greek "wanderer," those five bright "stars" that we unfixed and moved about in the heavens.
Scientists now speculate that Neptune lived its youth closer to the sun, between Saturn and Uranus, possibly. Gravitational play among the early solar system's planets launched it out to its current resident address at 2.7 billion miles from the sun. How can this happen? You can see it demonstrated on this web site if you play around with the planet Masses and orbits. I've been able to get planets orange and purple to switch positions by manipulating the orbit size of the white planet.
Many of the nearly two hundred planets discovered orbiting nearby stars are very large and very close to their home stars. Any earth-like planets would have been sadly ejected into interstellar space (or into the sun) as these big bullies made their way inward. For astronomers hoping for familiar earth-like planets, this does not bode well for their numbers in the galaxy. It might be that we were fortunate to have a Jupiter that settled 483 million miles out and stayed there. It might have chucked Neptune out a bit further, but at least it didn't consign us to a frozen existence billions of miles from our sun.
Good stuff coming in from Saturn this past week. Check it out here. As of this writing, a close pass of Dione is just three hours away.
