Where When How — March/April 2017
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Skywatch - The Night Sky
Dr. Thomas Lesser


Spring begins March 20th

The Sun will be directly over a point on the equator on March 20th, making it the equinox, one of the dates on which we note the changing of the seasons, from Winter to Spring in the Northern Hemisphere, and from Summer to Fall in the Southern Hemisphere.

As Spring begins, four planets will be visible in the night sky: Mars, Jupiter, Saturn, and Venus. Once the Sun sets and the sky begins to grow dark, a bright, red, star-like object will become visible low in the western sky; this is Mars. Look to the east and you will see another bright, star-like object, the largest of all the planets, Jupiter. If you draw a line across the sky from Mars to Jupiter, you will have marked the zodiac.

The zodiac is a band across the sky to which we must look to see the planets. Mars is seen against the background of stars of Aries, the Ram. Aries has no bright stars, so it is good at this time to have Mars to mark it. Eastward along the zodiac is the bright red-orange star Aldebaran, the red right eye of Taurus, the Bull. To the Greeks, Taurus represented Jupiter when he transformed himself into a pure white bull. In this form Jupiter carried Europa across the sea to Crete.

As you look eastward from Aldebaran you will easily be distracted by the bright stars a little lower in the sky. This is Orion and its seven bright stars form the outline of the Hunter's body: two mark his shoulders, two his knees and three his belt. Below Orion is the brightest star in the nighttime sky, Sirius, in Canis Major, the Large Hunting Dog. While beautiful to observe, neither Orion nor the Large Dog are part of the zodiac

To the east of Orion and higher in the sky are two bright stars of about the same brightness. These are Castor and Pollux, the heads of the twin brothers, the Gemini. Gemini is part of the zodiac. East of Gemini is another zodiacal constellation with no bright stars, Cancer, the Crab. Still farther east is another bright reddish star, Regulus, which marks Leo, the Lion. Regulus is also the point at the base of a backwards question mark. The top of the question mark is Leo’s head and a triangle of fainter stars toward the East marks the Lion’s hind quarters and tail. Don’t worry if you cannot see a Lion here, most people can’t, but you should be able to find the backwards question mark.

East of Leo and low in the sky is Jupiter and nearby a bright star, Spica, a grain of wheat being held in the hand of Virgo, the goddess of the harvest.

Just before midnight, Saturn will rise in the east. And just before sunrise, Venus rises above the eastern horizon. Venus is very easy to locate since it is the third brightest object in the sky, only the Sun and Moon are brighter, and Venus looks more like a bright white star.

The night of April 22-23 is the maximum of the Lyrid meteor shower. On a clear dark night, with a dark location, you may see a dozen or so meteors or shooting stars per hour. While that is not an overwhelming number, it does mean that you are more likely to see a shooting star, especially if you look between midnight and dawn. Shooting stars are not stars at all, they are meteors, pebble-sized bits of dust burning up as they race through the Earth’s atmosphere some 50 miles up.

This column is prepared especially for TCI stargazers by DR. THOMAS LESSER, former Senior Lecturer at the American Museum-Hayden Planetarium and a frequent visitor to the Caribbean.