Download March 2013 - Joliet Junior College

MARCH 2013 ASTRONOMY
From the Trackman Planetarium at Joliet Junior College
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Jupiter is the only major planet visible in the evening sky during March. Saturn is
working its way into the evening sky, but the change of time pushes back
Saturn’s rising time until 11 pm. By the end of March, Saturn will be rising at
9:30. Venus and Mars are too close to the sun to be observed. Venus crosses
behind the sun on March 26th. Mercury crosses in front of the sun on March 3rd
and will continue orbiting west until it reaches its maximum western distance
from the sun on March 31st. The sun will cross in front of Mars in early April.
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The sun sets at 6:50 pm at mid-month so good viewing doesn’t start until 7:30
pm. Orion is now in the western sky after dark. The two bright stars directly
overhead are Castor and Polux which mark the heads of the Gemini twins. To
the left of Gemini is Cancer. The stars in Cancer are too dim to be seen in
anything but very dark skies, but a binocular search through Cancer will find the
Beehive star cluster. Next to Cancer is Leo the Lion. The red star, Regulas,
marks Leo’s chin and above Leo is a summer favorite - the Big Dipper. If you
can see the two stars that make up the middle star of the Big Dipper’s handle,
you have good eyesight according to the Native Americans and the ancient
Egyptians. (They all must have passed because there are no pictures of ancient
Egyptians or a Native Americans wearing glasses!) The two stars that mark the
outer edge of the dipper cup are the “pointer stars” and if you follow them to the
north you will find Polaris or the North Star.
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Comet Panstarrs should be visible low in the western sky after sunset from
March 16th thru March 24th. It will appear as a star with a gaseous tail. Binoculars
should help you find Panstarrs, but don’t use binoculars until after the sun has
set. It only takes a second to be blinded by the sun magnified in binoculars.
Comet Ison will be in the evening skies at the end of November and first part of
December. Ison is still predicted to be the brightest comet in the past hundred
years. Estimates are that it will be as bright as the moon and might be visible
during the day. However, estimates of a comet’s size and brightness can change
as the comet orbits closer to the sun.
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The Vernal Equinox (start of spring) is on March 20th at 6:02 am. Since the first
day of winter, the sun has been crossing the sky slightly higher every day. On
the equinox the sun is directly above the Earth’s equator and will begin shining
above the northern hemisphere until next September. On the equinox, the sun is
above the horizon for twelve hours and below the horizon for twelve hours.
After the Vernal Equinox, the farther north you go the more hours of sunlight
you get each day. (The sun rises at the north pole on the Vernal Equinox and
won’t set again until September.) Our communication satellites orbit at 22,000
miles above the equator and that puts the communication satellites in the path of
any Coronal Mass Ejections emitted from the sun when it is above the equator.
The charged particles from those ejections can disrupt your television signals or
cell phone signals for a day or two on either side of the equinox. The
communication satellites are in a geosynchronous orbit - an orbit that is at just
the right altitude and speed to keep them over the same place on Earth as the
Earth rotates.
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On March 10th we change to Daylight Saving Time. Set your clocks - and all
those electronic gadgets - ahead one hour. If we didn’t change to Daylight
Saving Time, in June the sun would rise at 4:20 am and dawn would begin at 3:00
am. And the latest summer sunset would be at 7:30 pm.
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March 26th will be the tenth anniversary of a meteor exploding over Park Forest,
Illinois. Parts of the Park Forest Meteor damaged two houses and went through
the roof of the fire station. About 40 pounds of meteorites have been recovered
from the space intruder. The meteor that exploded over Chelyabinsk, Russia last
month is estimated to have weighed 10,000 tons and was traveling at 46,000 mile
per hour. Only one two pound piece and tiny fragments have been recovered
from the Chelyabinsk Meteor. Siberia has been the target of several other “hits”
from space intruders. The largest was either a comet or asteroid that explode
over Tunguska in 1908. The largest meteor or asteroid to hit in what is now the
United Stats happened at Manson, Iowa 74 million years ago. Hidden about 300
feet below the surface of Manson is a crater that is 24 miles in diameter. There is
a five mile wide asteroid crater that is 280 million years old about 150 feet below
the surface in DesPlaines where Interstate 294 (Tri-State) crosses Golf Road.
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Joliet Junior College (JJC) will host its open house, Discover JJC, on Saturday,
March 3, from 9 a.m. to noon on the Main Campus, 1215 Houbolt Road in Joliet.
Faculty and staff will be on hand at Discover JJC to answer questions about JJC’s
academic programs, financial aid and scholarships
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The Public Shows at the Trackman Planetarium during March are: “The Solar
System” on March 7th at 6:30 pm; “Asteroids, Meteors and Comets” on March 12th at
7:30 pm; “A Trip through the Stars” on March 21st at 6:30 pm; “Search for Intelligent
Life” on March 26th at 7:30 pm. All the free Public Shows start with a dome
presentation displaying the current skies.
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Art Maurer
Director -Trackman Planetarium
Joliet Junior College
815-280-2601
([email protected])