Friday, November 15, 2013

November: A Comet; Meteor Shower

We have been busy this month! Getting out to the porch to view has been difficult this month. Even in clear conditions, November has been lost in searching for the comet ISON. We have spent several early morning hours searching and scanning the lower horizon! Our problem is the horizon! Just too many trees, so we track the icy rock on line. COMET ISON UPDATE: Reports of naked-eye sightings of Comet ISON are coming in from around the world. Experienced observers put the comet's magntitude at +5.5 on Nov. 16th. This means it is now fully 10 times brighter than it was only three days ago before the outburst. To the naked eye, ISON appears as a faint smudge of pale green light low in the pre-dawn sky. The view through a telescope is more dramatic. The comet's tail has become a riotous crowd of gaseous streamers stretching more than 3.5 degrees across the sky.

Monitoring is encouraged. Comet ISON rises in the east just before the sun. Amateur astronomers, if you have a GOTO telescope, enter these coordinates. Dates of special interest include Nov. 17th and 18th when the comet will pass the bright star Spica, making ISON extra-easy to find. Sky maps: Nov. 15, 16, 17, 18,19.

I’m going to miss the monthly meeting and the next TPML Hilltop Event. The clouds may put an end to any viewing at this month’s event!

This will be another year missing the great meteor shower of the past, always hoping for another “Storm”, like we witnessed in 98. In fact, the 2013 Leonid meteor shower, scheduled to peak overnight Saturday night and early Sunday morning (Nov. 16 and 17), are likely to be a major disappointment, partly because of the expected lack of any significant activity, but mainly because of the moon which unfortunately will be full, flooding the sky with its bright light. Those turn-of-the-century Leonid showers — and their accompanying hype — are still remembered by many, but it is important to note that any suggestion of a spectacular Leonid display this year is, to put it mildly, overly optimistic. [Amazing Leonid Meteor Shower Photos by Stargazers] The Leonids are named for the constellation Leo, the Lion—the point in the sky where many of the meteors seem to originate.

The meteors are caused by the Comet Tempel-Tuttle, which sweeps through the inner solar system every 33.3 years. Each time the comet passes closest to the sun it leaves a "river of rubble" in its wake; a dense trail of dusty debris. A meteor storm becomes possible if the Earth were to score a direct hit on a fresh dust trail ejected by the comet over the past couple of centuries.

The 2013 Leonids are expected to show only low activity this year with 10 to maybe 20 meteors per hour at best. The "traditional" peak for the Leonids is scheduled for the predawn hours of Nov. 17 and the full moon will be not too far away, shining within the constellation Taurus, making observations very difficult.

Such meteor storms have indeed occurred with the famous November Leonids. For instance, in 1833 and 1966 meteor rates of tens of thousands per hour were observed. In more recent years, most notably 1999, 2001 and 2002, lesser Leonid displays of up to a few thousand meteors per hour took place.