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The Sky This Week, 2011 April 12 - 19

A Big Anniversary
Satc8_110407_0302_01small.jpg
Saturn, 2011 APR 7, 03:02 UT
Imaged with a 20-cm (8-inch) f/10 Schmidt-Cassegrain
and 2X Barlow lens.  Note storm cloud in
northern hemisphere cloud belt

The Moon continues to brighten the evening sky this week, waxing to her Full phase on the 17th at 10:44 pm Eastern Daylight Time.  April’s Full Moon is popularly known as the Grass Moon or Egg Moon in Native American skylore, but it also happens to be a very important marker in the religious calendars of Jews and Christians.  Known as the Paschal Moon, it sets the beginning of Passover and fixes the date of Easter.  Luna spends the week coursing through the springtime constellations, passing six degrees south of the bright star Regulus in the constellation of Leo, the Lion on the evening of the 13th.  On the 16th she lies eight degrees south of golden Saturn, and on the following night her bright full visage lies just four degrees southeast of the bright star Spica.

April 12th is a very momentous day in the history of space flight.  Fifty years ago a young test pilot from the Soviet Air Force named Yuri Gagarin became the first human to enter space aboard Vostok-1.  In 108 minutes he circumnavigated the globe, launching from and landing in what is now Kazakhstan.  He lifted off from the same launch pad used for Sputnik-1 less than four years previously, and this same launch pad is still used today to dispatch crews and supply craft to the International Space Station.  The 12th is also the 30th anniversary of the first flight of the Space Shuttle, with astronauts John Young and Robert Crippen riding the orbiter Columbia into orbit for a two-day “shakedown” flight.  Since that time there have been over 130 shuttle flights.  Both Young and Crippen were Navy aviators, and it just so happens that the 12th is also the 100th anniversary of the first man to qualify as a Navy pilot when LT Theodore Ellyson received his aviator’s wings.  Indeed our progress over the last century has been remarkable.  To celebrate this special day, many people now observe “Yuri’s Night” each year on April 12th, either as part of a larger group or by themselves.  This year, if it’s clear and you have a telescope, set it up and show a child the wonders of the Moon or Saturn’s rings on Yuri’s Night or any time this week.  You may just inspire the “next Yuri” to aim for higher frontiers.

The lone evening planet that’s available for inspection right now is Saturn, but there are few sights in the sky which offer more fascination than this distant ringed world.  Saturn is available for viewing all night, with the best time to admire his form falling in the late evening hours.  Few telescopic sights evoke the mysterious nature of space than the sight of the planet’s yellow globe suspended inside the rings.  The planet is currently tipped about 8 degrees to our line of sight, and on nights of steady air a small telescope should reveal the gap in the rings known as Cassini’s Division and some of the subtle cloud belts in the exposed northern hemisphere.  Larger instruments should be able to show the remnants of a huge storm that erupted on the planet a few months ago in the form of white patches in the darker clouds of the North Equatorial Belt.;

Morning twilight still finds dazzling Venus resolutely rising just before the Sun.  Even though she’s quite low in the southeast at the time, she should be quite easy to spot half an hour before sunrise if you have a clear horizon.;

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