Astronomy 101
In honor of the giant stack of papers I have been grading all weekend, I thought I would put together a short list of the most common misconceptions I seem to keep running across. Some of these come from this year's class, some are from years past. I don't expect the general public to know these things (though it wouuld be nice), but I sometimes wonder how students taking an astronomy class can continue to misunderstand these things at the end of an entire semester.
1) The phases of the moon are not caused by the Earth's shadow falling on the moon. The phases of the moon (in the shortest way I can think of to explain it) are created because at any given time, the Sun illuminates the half of the moon which happens to face it; the other half of the moon is dark. As the moon orbits the Earth each month, we different amounts of the light and dark sides each day, depending on where the moon is with respect to the Earth and Sun.
Addendum to #1: When the Earth's shadow does fall on the moon, that is called a lunar eclipse. A lunar eclipse does NOT occur because the moon "falls and hits the Earth". (That's technically an answer from someone else's class and not mine, but I think it bears sharing).
2) Earth orbits around the Sun, not the other way around. In addition, we see the Sun and stars "rise" and "set" each day simply because the Earth is rotating. The stars are (more or less) fixed in the sky.
3) The Sun is a star, just like all the stars you see in the sky at night. The only reason it is special (and might appear to some to be a completely different kind of entity) is its close vicinity to Earth.
4) The seasons are not caused by the Earth moving closer to and farther away from the Sun during the year. The seasons mostly arise because of the Earth's rotation axis. When the Earth's axis is tilted slightly toward the Sun, the N. hemisphere has summer; at the same time, the S. hemisphere is tilted slightly away from the sun and they experience winter. Six months later, the opposite happens and the N. hemisphere has winter, the S. hemisphere has summer.
Anyway, there you go. A brief astronomy lesson. It's back to grading for me.
1) The phases of the moon are not caused by the Earth's shadow falling on the moon. The phases of the moon (in the shortest way I can think of to explain it) are created because at any given time, the Sun illuminates the half of the moon which happens to face it; the other half of the moon is dark. As the moon orbits the Earth each month, we different amounts of the light and dark sides each day, depending on where the moon is with respect to the Earth and Sun.
Addendum to #1: When the Earth's shadow does fall on the moon, that is called a lunar eclipse. A lunar eclipse does NOT occur because the moon "falls and hits the Earth". (That's technically an answer from someone else's class and not mine, but I think it bears sharing).
2) Earth orbits around the Sun, not the other way around. In addition, we see the Sun and stars "rise" and "set" each day simply because the Earth is rotating. The stars are (more or less) fixed in the sky.
3) The Sun is a star, just like all the stars you see in the sky at night. The only reason it is special (and might appear to some to be a completely different kind of entity) is its close vicinity to Earth.
4) The seasons are not caused by the Earth moving closer to and farther away from the Sun during the year. The seasons mostly arise because of the Earth's rotation axis. When the Earth's axis is tilted slightly toward the Sun, the N. hemisphere has summer; at the same time, the S. hemisphere is tilted slightly away from the sun and they experience winter. Six months later, the opposite happens and the N. hemisphere has winter, the S. hemisphere has summer.
Anyway, there you go. A brief astronomy lesson. It's back to grading for me.
posted by Meredith | 1:06 PM
2 Comments:
Aw...my little nerd! That probably felt really good to get that out. I should do one on grammar and spelling.
It really did feel good. I'm currently contemplating taking off points from someone's paper who spelled "sky" as "ski". It's been a rough stack of papers for me.
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