Pluto: planet or pretender?
You over-50s out there will probably remember the hary-scary 1961 movie “Voyage to the Bottom of the Sea” in which the Van Allen Radiation Belts threatened our planet when they caught on fire. Nobody ever told me, a mere stripling, that it could never happen; boy, was I scared for the longest time. Now I stand in awe of the Belts — yet another example of the marvels of creation in our very own space backyard. If it weren't for that movie, I reckon few of us would ever have heard of these belts of energetic charged particles trapped around the earth by our planet's magnetic field. As for me, personally, until I started to do a little reading about the universe ten years ago I had no idea what wonders were stirring around us — at a distance, admittedly — every moment of our lives. As for our own solar system, I knew it contained nine planets, some of which were harried by a number of busybody moons that kept circling overhead in constant vigil. I had heard of asteroids and comets, and rings around Saturn; I was aware that our sun contained a few mysteries that I expected astronomers would soon solve. And that was about it — oh yes, and the Van Allen Radiation Belts.
Probably most Dawn to Dusk readers are in the same boat I was in for many years. But you know something, we could hardly be wronger. Our own sun is surrounded by a marvelous zoo-full of fascinating creatures, even the best-known of which pulsate with mystery. And as they learn more, astronomers are continually being kept on their toes trying to make sense of it all, as is illustrated by the recent kafuffle over defining a planet. Only two weeks ago newspaper science writers were predicting that we were about to be told our solar system contains twelve planets, not the nine we were acquainted with. But it was not to be! Instead,
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delegates at the International Astronomical Union meeting in Prague have just demoted Pluto to the status of dwarf planet. So instead of the nine planets we had until now, and instead of the twelve we thought we would have, we are now down to only eight. (According to some reports, American astronomers are up in arms over the change — after all, Pluto is the only planet [sorry, ex-planet] discovered by Americans.)
However, this change in status should not be interpreted as indicating a shrinking solar system. Rather, a major reason for the change is the discovery of a “sea of rocks” beyond Neptune's orbit in what is now known as the Kuiper Belt, extending the limits of our solar system by about 40%. In order to be considered a planet, a body has to be much bigger than any other similar bodies in the vicinity. Before 1992, Pluto was the only known rocky body revolving around the sun past Neptune. In that year a few bodies with diameters of hundreds of kilometers were discovered in Pluto's general neighborhood. Within four years that number had risen to three dozen, while now it numbers in the hundreds. Since some of them rival Pluto in size, it was only a matter of time before a controversy arose — should Pluto be demoted or some of these other bodies promoted? The plotters against Pluto have won the day. At least for the time being.
Though every day mysteries are being turned into marvels, new marvels and mysteries pop up at the same rate, or even faster. (See the account of the discovery of many new moons in No-God of the no-gaps.) I believe that acknowledging and bowing before a supremely powerful designer and creator makes a lot more sense than worshiping a fortuitous, miracle-working “explosion” (the big bang) does, don't you? |
