If the Groundhog emerges tomorrow from his burrow in the bank and sees this –
– it won’t be February 2 at dawn, it will be November 17 at three in the morning, and what he sees will be a record-breaking meteor shower, like the one that Abraham Lincoln saw in 1833. Over 100,000 per hour – around 30 per second, a hundred or more visible at any instant.
(See the end note about enlarging illustrations.)
Either that, or the groundhog will be looking at one of the pages about meteors in the upcoming new edition of the Astronomical Companion.
I contrive this pretext for giving you a preview of the illustration because I’ve been working obsessively to make it a compromise between realism and pizzazz, and would be interested to know what you think.
The caption for the illustration will say:
If Earth were again to meet as dense a clump in the Leonid stream as it did in 1833, there would be a multitude of simultaneously visible meteors. Here we represent them by stars appearing to fall, as they were imagined to be, and give them the stars’ spectral colors, exaggerated. Meteors are more likely to be white, some with tinges of color. There are 181 in the picture, because I have spare stars fainter than magnitude 4 from falling.
You are forced to see, as Denison Olmsted saw, that the meteors of a shower appear to radiated from a point, therefore must be in paths parallel to each other, therefore must constitute a stream, therefore – since the shower recurs annually – must be in an orbit around the Sun.
Notice the point with a mark like a steering wheel for “Earth’s direction of motion.” The planet meets the stream of particles like a car meeting a swarm of gnats.
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This weblog maintains its right to be about astronomy or anything under the sun.
ILLUSTRATIONS in these posts are made with precision but have to be inserted in another format. You may be able to enlarge them on your monitor.
One way: right-click, and choose ”View image” or ”Open image in new tab”, then enlarge. Or choose ”Copy image”, then put it on your desktop, then open it. On an iPad or phone, use the finger gesture that enlarges (spreading with two fingers, or tapping and dragging with three fingers). Other methods have been suggested, such as dragging the image to the desktop and opening it in other ways.
Sometimes I make improvements or corrections to a post after publishing it. If you click on the title, rather than on ‘Read more’, I think you are sure to see the latest version. Or, if you click ‘Refresh’ or press function key 5, you’ll see the latest version.