Beyond Pluto
by John Davies
(Notes written in November, Year 2)
Read this book quickly!
| The author is a noted planetary astronomer and, like most of the people he mentions in this book, actually has a minor planet named for him (9064 Johndavies, found in 1993 floating around outside the orbit of Neptune). Apparently the good old rule against so honoring still-vertical real estate developers and politicians does not much appeal to planet discoverers. But let that pass; it doesn't much appeal to county commissions either, at least in Georgia where everything above the level of mileposts seems to be named for a living person. | March 16, Year 4: Further down the page I suggested following up what the book says, and sure enough, Trujillo and Brown and others have identified some large objects in the Kuiper Belt and even one in the Oort Cloud since Davies' work appeared. You can view a very good illustrated page on the planetoid Quaoar and an early report on the Oort object Sedna, but by the time you read this those pages will be out of date too. Your best bet for catching the most recent discoveries will be a Google search or regular visits to a general news site like CNN. |
OK, let me start again. The things you'll find special about Beyond Pluto are that (1) it comes from someone who knows all the people, reads all the publications, and has far better than average skill in explaining what the hell astronomers do and (2) it's dated 2001 and reports discoveries well into that year. Use the book to bring your information about the outer solar system up to date, but don't delay, because a lot of it will no longer be up to date sometime in, I estimate, February of the Year 3.
The part of the world that interests Davies doesn't lend itself to dramatic illustrations. (I add, in hope, yet.) You've probably seen photos of Io volcanizing or Uranus with its rings. None of that here: The objects (iceballs, gravel banks, big rocks, etc.) out beyond Neptune are so far away from us that their light makes only a faint dot in the picture, and even finding the dot takes skill and luck. Photos that show objects such as Chiron or trans-Neptunian object 1996 TO66 will excite solar system astronomers but leave most other readers a little bewildered. Davies has cleverly made a book for readers who are not astronomers: The telescopic images and the graphs are interspersed with candid pix of the people who really get stirred by this research.
Just what is it that stirs them? Many astronomers got hooked on starwatching as kids, and many found enchantment in viewing Jupiter's moons or the crescent Venus through their telescopes. Looking for comets is rewarding because you get to go on CNN if you find a flashy one. But the idea of studying nearly invisible bodies in an unknowable region didn't appeal to lots and lots of people. Then the Apollo and Voyager era began to reveal how very weird our solar system is: Moon rocks that could have come from Oregon, clouds of teeny satellites circling giants that don't seem to need them, even an atmosphere around the coldest of planets. The place got more mysterious as we came to know it better . . . and mystery is a great mover of curiosity.
Davies doesn't bring this point up: Solar system astronomy also got a boost from geologists who kept saying a comet killed the dinosaurs and another one could do for us. Since the 1980s we've acknowledged a vital interest in knowing what the universe has aimed at us.
Finally, the outer part of the system, where it's cold and dark (no very fast chemistry going on) and things seldom run into one another (no drastic physics either), may still hold some of the stuff that the Sun and planets grew from. By learning everything we can about matter out there, we may learn much about what's in here. The region beyond Neptune has become an attractive field for study.
Some quite ingenious people are at work on it, too. Eileen Ryan buys ice from the supermarket, compacts it into balls, and shoots aluminum bullets at it to see what kind of fragments result When Comets Collide. Scientists in the U.S. and Taiwan plan to use cheap instruments to survey big areas of sky for comets that pass in front of distant stars. Chad Trujillo writes computer code to pick trans-Neptunian objects out of photo sequences. Jane Luu and Dave Jewitt spend untold hours in the nosebleed-thin air on top of Mauna Kea making photographs to run through Trujillo's filters. Retired industrialist Warren Offutt dedicates his own observatory to "recovering" once-found planets (i.e., measuring their position weeks or months after their discovery so that orbital calculations can work from extended data). Mike Brown tests scenarios to explain why some objects look red at one sighting but blue at another. It's a great strength of Davies' book that he talks with these folks at meetings and parties, knows their children's names, follows their work closely, and then writes it all down in a book.
I'm tempted to suggest that Beyond Pluto should have been issued in looseleaf form with annual updates. The book is clearly a kind of snapshot: Here's where everybody has gotten to in 2001, but check back with us later. (Click here, for example.) If you believe that science makes a good story, here are a few dozen good stories about smart, obsessed people trying to figure out very hard questions. No endings, just stories in progress.
(You may well ask: If it's called Beyond Pluto, why do astronomers divide the solar system at Neptune's orbit? Right, A, because Beyond Neptune sounds so lame and, B, because in terms of dynamical physics Neptune swings a lot more weight than Pluto does. Indeed, in some respects Pluto fits better with the trans-Neptunian objects than it does with its neighbor planets. And, C, because Pluto's orbit cuts inside Neptune's anyway. There is a chapter about this, oh yes.)
| Approved Ben Teague web site |
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Beyond Pluto