Skywatch Line for Monday and Tuesday, March 20th and 21st, 2017

This is the Skywatch Line for Monday and Tuesday, March 20th and 21st.

The Sun sets at 7:08PM; night falls at 8:43. Dawn breaks at 5:21 AM and ends with the Sun rising at 6:56.

The Vernal Equinox took place at 6:29 Monday morning, signaling the beginning of astronomical spring. Astronomers define Spring as that point when the ecliptic (the Sun’s path across the sky) and the celestial equator (the projection of Earth’s equator onto the sky) cross with the Sun climbing higher on the ecliptic.

The southwest evening sky contains three bright planets and one dim one, all in Pisces. Pisces houses Venus, Mercury and Uranus. Venus is brightest and lowest, blazing at minus fourth magnitude but appearing only 2 percent illuminated. Shortly, it will disappear behind the Sun. Venus sets at 8 PM. Weather permitting, observers can enjoy a rare event. Tuesday, Venus sets about 30 minutes after the Sun, and rises 33 minutes before the Sun on Wednesday. Clear western and eastern horizons afford views of the planet before those times.

Ten degrees to Venus’ upper left is Mercury, beginning its best appearance of the year. Mercury blazes at minus first magnitude, appears about 84 percent illuminated and six degrees high. Mercury sets at 8:15 PM. Nine degrees to Mercury’s upper left is much dimmer Uranus, shining at sixth magnitude and about 15 degrees high; Uranus sets at 9 PM. Fifteen degrees to Uranus’ upper left is first magnitude Mars, now in Aries. It appears as a tiny red dot but 29 degrees high. Mars sets at 10:20 PM.

Nightfall reveals dim seventh magnitude asteroid 4Vesta. It lies about 1 degree below the star Upsilon Geminorum and is best observed at 8:30 PM.

Jupiter rises at 8:39 PM in Virgo. It glows at minus second magnitude, outshining first magnitude star Spica below. Jupiter is best observed at 2:20 AM. Telescopic observers can witness the Great Red Spot, a giant storm, at 4:03 AM on Tuesday and at 11:54 PM on Wednesday. Jupiter remains up the rest of the night.

Saturn rises at 2:12 AM in Sagittarius. The Ringed Planet appears a creamy white 0.5 magnitude twenty-two degrees high in the eastern sky.

The Last Quarter Moon rises, also in Sagittarius, at 2:46 AM. Its minus ninth magnitude will washout dim deep sky objects. The Moon appears 30 minutes large and about 43 percent illuminated. Wednesday, a slightly fainter and slimmer Moon rises about 3:33 AM.

A chain of stars wraps itself around Polaris, the Pole Star; this group is the constellation Draco, the Dragon. Draco is ancient, going back to the Mesopotamians. Most legends picture dragons as we do, with horns, wings and multiple heads. Several Greek legends have the dragon guarding the Golden Apples or the Golden Fleece. In our night sky, Draco seems to continue his role as protector of the Pole Star. However, when the Pyramids were built, Thuban, one of Draco’s stars was, itself, the Pole Star. Several of the Pyramids were oriented to it.

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