dipper@utastro.UUCP (Debbie Byrd) (12/09/85)
The planet Saturn would float on water. More -- after this. December 9 Why Saturn Would Float Saturn is a huge planet, many times larger than Earth. But in principle this giant planet would float on water, if you could find an ocean large enough to hold it. Saturn would float because it's not very dense. There's a big difference between how massive something is -- and how dense it is. Saturn has nearly a hundred times as much matter as the planet Earth -- and so it's said to be more massive. But that matter isn't packed very tightly. Saturn is much less dense than Earth. Earth wouldn't float on water, even though it's smaller than Saturn -- because it's more dense -- with more matter squeezed into each given unit of volume. Saturn is larger and contains more total matter. But its matter isn't squeezed in very tightly. Saturn consists mostly of very light gases. These gases are lighter than water -- so they'd float on water! It'll soon be pretty easy to see Saturn in the predawn sky. It's near another planet which should now be visible to the eye -- the planet Mercury. Saturn may also be visible to the eye now. Or you may still need binoculars to see it. From Earth, Saturn and Mercury are now near the same line of sight as the sun. In other words, they're low in the east before dawn. In another week, they'll be higher in the sky -- definitely visible to the eye -- and very near each other! You may want to take a look. Script by Deborah Byrd. (c) Copyright 1984, 1985 McDonald Observatory, University of Texas at Austin