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Back-to-School Quizzie!
Science >
Ah... it's back-to-school time. How about we have a friendly little astronomy quizzie to put us all back into School Mode? Those of you who read here regularly know that this is not a genuine quiz so there is no need for clammy hands and shortened breath. And there are only three true-or-false questions. So sit back and enjoy a little exercising of the grey cells.
1. Only a select few people on the planet can see an eclipse.
OK, admittedly that was sort of a trick question. I should specify lunar or solar eclipse. Few people see a solar eclipse in a lifetime; most everyone on the planet can see a lunar eclipse though. Why?
An eclipse is basically one body casting a shadow on another. If the Moon squeezes in between the sun and us, for example, it can cast a shadow somewhere on Earth. But it's just a pinprick of a shadow, sometimes only tens of miles across. And the shadow races across the surface of our planet at about 1000 miles per hour.
This is a solar eclipse, and it is an amazingly ethereal phenomenon to observe. But you have to be in the exact right place to be in "the umbra" or full shadow. To see one you will probably have to get up and go somewhere. If you are not content on actually traveling to see one, be patient, your area probably will get a total solar eclipse in the next three or four centuries.
A lunar eclipse is a different duck. When we cast a shadow on the Moon, it's no tiny pinprick. Our shadow can cover the entire Moon! The benefit of a lunar eclipse is that everyone on one side of the earth can see it. It's a free show from your own backyard. And if you miss one you only need wait another 6 months or a year to see it again. In the average lifetime one can see literally dozens of them.
2. Your date of birth determines which astrological sign you are.
This really is an astronomy-related statement! We are told that the moment of your birth determines what "sign" you are; whether you are Capricorn or Aquarius or Leo, etc. And your sign is determined by which constellation the sun is in at that special moment.
But the charts that are used to tell us what our sign is were made thousands of years ago. Here's the problem. Since that time our planet has wobbled ever so slightly in its spin position - not much, but enough to "shift" the constellations through the calendar a wee bit.
So, for example, on January 27 a few thousand years ago we would have found the Sun occupying the region in space dedicated to Aquarius. Since then, though, our wobble has shifted the January 27 sun into Capricorn.
Meaning, although the newspaper horoscope will peg a baby born then as an Aquarian, the sun was really in Capricorn at her birth. So what sign is she - Aquarius or Capricorn? Good question. And the same dilemma follows for nearly everyone reading this now: Nearly all of us are off by one sign. More than 90% of the people reading horoscopes have been reading the "wrong" sign. Hmmm…
3. Pluto is a planet.
This is an emotional subject as of late! Since its discovery in 1930, this little guy has been considered a planet. And why not? It was the next heavenly body discovered beyond Neptune; it should be a planet.
But wee Pluto has been trying to tell us something since those early days.
For one thing, it is a very, very small orb, smaller than our country let alone our Moon and a handful of other heavenly objects not considered planets. Its orbit is way wacky; it's outside the regular plane of the rest of the planets, and sometimes it's closer to the sun than Neptune.
And for the last ten years we've seen a whole truckload of other Pluto-like objects out in the deep areas of our solar system, beyond Neptune, seemingly filled with icy bodies of all sizes, one bigger than Pluto itself.
Which is why it was agreed by voting astronomers recently that maybe Pluto should just be considered the "first found" of those trans-Neptunian objects, aka Kuiper Belt Objects.
But the controversy isn't over. A small but vocal group of astronomers who want to keep poor Pluto as a proper planet is demanding a recount. So stay tuned, maybe we won't need to downsize the little guy - yet.
Get all three correct? If not, no worries. None of these statements were too black and white. That's the nature of science; lots of gray, a little black and white. Until next time, clear skies!
Posted by Mark Ritter at 2006.09. 3 08:12 PM | Comments (0)
