Death by Black Hole:
and Other Cosmic Quandaries
by Neil deGrasse Tyson
Just like Hillary.
Anthony Doerr is the author of two books, The Shell Collector, and About Grace. His fiction has appeared in numerous publications, including the O. Henry Prize Stories, Paris Review, Atlantic Monthly, Zoetrope: All Story, Tin House, and The Best American Short Stories. The Shell Collector, a volume of eight short stories, was published in 2002 and won the Barnes & Noble Discover Prize, two O. Henry Prizes, the Rome Prize, and the Ohioana Book Award. It was a New York Times Notable Book and an American Library Association Book of the Year. About Grace, his first novel, was published last year and was named one of the Best Books of 2004 by the Washington Post, won the Ohioana Book Award again, and was a finalist for the PEN USA fiction award.
That's the guy who hates Pluto!
SaturnThey range in size from a centimeter or so to several meters. A few kilometer-sized objects are also likely.
by Bill Arnett
The Nine Planets
Saturn's rings are extraordinarily thin: though they're 250,000 km or more in diameter they're less than one kilometer thick. Despite their impressive appearance, there's really very little material in the rings -- if the rings were compressed into a single body it would be no more than 100 km across.
The ring particles seem to be composed primarily of water ice, but they may also include rocky particles with icy coatings.
Voyager confirmed the existence of puzzling radial inhomogeneities in the rings called "spokes" which were first reported by amateur astronomers (left). Their nature remains a mystery, but may have something to do with Saturn's magnetic field...
The origin of the rings of Saturn (and the other jovian planets) is unknown. Though they may have had rings since their formation, the ring systems are not stable and must be regenerated by ongoing processes, perhaps the breakup of larger satellites. The current set of rings may be only a few hundred million years old.
BFLR = Bump for later reading
