When you wish upon a shooting star…it’s probably a meteoroid

Perseid Meteor 8/12/08
Creative Commons License photo credit: aresauburn™

The Perseid Meteor Showers, which occur every year around this date, are caused by the comet Swift-Tuttle. The comet itself was discovered in 1862, and could be seen again with binoculars in 1992. Calculations have shown that the comets witnessed in China in 188 A.D. and 69 B.C. were most likely the same comet. It is suspected that the comet should pass close enough to the Earth in 2126 to be visible to the naked eye (looking forward to that!) The comet should pass with in one million miles of the Earth in 3044 (a near miss.) The comet is approximately six miles across, which is the estimated size of the comet that killed off the dinosaurs millions of years ago.

Although the comet itself is currently far away, the Earth passes through the comet’s debris every year. The majority of the debris (meteoroids) is pea- or marble-sized and enters Earth’s atmosphere at roughly 133,200 mph (which is roughly 2,220 times faster than a car on the freeway, and 12,100 times as fast as I can run at top speed.) As the particle enters the atmosphere, it compresses the air in front of it, which heats it up. The temperature rises to about 3,000 degrees Fahrenheit, which vaporizes the meteorite, creating the effect known as a “shooting star.”

Although a few of the meteorites could be seen last night and a few more tomorrow night, the best viewing time is in the predawn hours following tonight. In honor of such a spectacular natural occurance, the George Observatory in Brazos Bend Park will stay open from 9 p.m. tonight until 5 a.m. tomorrow morning

 This informational video was made for the 2008 Perseid Meteor Shower
The dates are slightly off, but all the other information is correct

Wherever you’re watching, you can use Twitter hashtag #meteorwatch to follow the action and ask questions!

Go Stargazing! October edition

David & Goliath II
Creative Commons License photo credit: maxedaperture

Jupiter remains well placed for observing this month.  It outshines everything except the Moon and Venus and is therefore easy to find in the south-southwest at dusk.  Venus continues to re-emerge into the evening sky.  Although it is low in the west southwest during evening twilight, Venus outshines everything in the sky except the Sun and the Moon, so viewers with clear views to the west southwest should be able to find it right after sundown.  Saturn has also emerged into the morning sky; face east at dawn to see it.  Late October is a good time to observe Mercury before dawn.  Greatest elongation (that is, greatest apparent distance from the Sun) is October 22.  You can look for about a week to either side of that date; Mercury is slightly brighter in the days following greatest elongation if it’s at dawn.  Mars is lost in the Sun’s glare this month and will remain out of sight until 2009. 

Sagittarius Region
Creative Commons License photo credit: makelessnoise

The Big Dipper happens to be to the lower left of the North Star at dusk this month; you’ll need a clear northern horizon to get a good look at it.  Sagittarius, the Archer, known for its ‘teapot’ asterism, is in the southwest (Jupiter is in Sagittarius).  Look for the enormous Summer Triangle, consisting of the stars Deneb, Vega, and Altair, high in the west.   As familiar summer patterns shift to the west, the constellations of autumn take center stage.  The Great Square of Pegasus is high in the east at dusk.  The star in its upper left hand corner is also the head of Andromeda.  Facing north, you’ll see five stars in a distinct ‘M’ like shape—this is Cassiopeia, the Queen.  Her stars are about as bright as those in the Big Dipper, and she is directly across the North Star from that Dipper.  In fall, while the Dipper is low, Cassiopeia rides high.

Moon Phases in October 2008:

1st Quarter      October 7, 4:05 am
Full Moon        October 14, 3:03 pm
Last Quarter    October 21, 6:56 am
New Moon       October 28, 6:12 pm

Our George Observatory remains closed while Brazos Bend State Park recovers from Ike.  The park hopes to reopen by October 11, and there is hope that our annual Astronomy Day at the observatory, set for Saturday, October 18, will proceed as scheduled.   Astronomy Day features special presentations and activities for the whole family from 3pm to 10:30pm.  Surf to www.astronomyday.org for more information. 

Sunday, November 2, is the first Sunday of that month.  Accordingly, we ‘fall back’ to Standard Time that morning at 2:00am. (We go from 1:59 am back to 1:00 am).  Don’t forget to set your clocks back one hour on Saturday night, November 1.  Enjoy your extra hour of sleep!