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| The star chart shows the sky at
1:00 AM on November 18 on the night of our star party beginning on November
17. The Leonids are so called because their radiant lies in the Sickle
of Leo, a kind of reverse question mark shown in gray lines, above.
The radiant of a meteor shower is the point at which the individual meteors
appear to converge when their paths are extended backward. (The gray star
merely shows the location of the radiant; there really isn’t anything special
there.)
Meteor showers are somewhat like driving through falling snow, especially at night. The flakes will appear to diverge from a single point in front of you, much like the meteors shown as gray lines on the star chart. As the chart shows, meteors may appear anywhere in the sky and travel in any direction. The Leonids originate from debris cast off by Comet Temple-Tuttle, discovered in 1855. As the earth passes through the comet’s orbit every year, we run into some of this debris. We are most likely to see a good display when we encounter the debris close on the heels of the comet, as we may this year. |
You can print a copy of this star chart so you can take it outside.
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| We have another new comet this
month, Comet LINEARWM1, discovered in December, 2000, by the Lincoln Laboratory
Near Earth Asteroid Research Program, hence the LINEAR designation.
Using automated equipment at White Sands, New Mexico, the LINEAR program
searches for asteroids or other objects that may one day be a threat to
the earth. When we find such a threatening object – not if
but when – it will very likely be through the efforts of a program like
LINEAR. In the meantime, LINEAR continues supplying us with a steady
stream of new comets.
At this writing, November 7, the present comet is at about mag 10, well below naked eye visibility, and even binocular visibility. So far, I haven’t been able to see it even with our 12” scope. But by the night of our star party, November 17, it is predicted to be about mag 5, which should be visible to the naked eye under good conditions. On the other hand, a less optimistic prediction has the magnitude at about 9, which should be easily visible in a scope. Whether you’re an optimist or a pessimist, come have a look with us. You can find more information in the December Sky & Telescope, and on the S & T website at http://www.skypub.com and at http://encke.jpl.nasa.gov. |