Skywatch April 2004

During the first week of April all five of the visible planets grace our evening skies as the Sun sets. Other features of this month include the Lyrid meteor shower and a partial solar eclipse visible in parts of the southern hemisphere.

As twilight encroaches with the setting Sun, look for the planets to pop into view by magnitude. Venus, the brightest, is the first to pop into view high above the western horizon. Jupiter is next to make his presence known, becoming visible above the eastern horizon below the Moon. Nearly due south, the next thing to pop into view by magnitude is the bright star Sirius of Canus Major. You will know this is not a planet because it is too low to be on the Ecliptic. Brighter than Mercury and Saturn and becoming visible before they do, are the stars Rigel of OrionÕs foot (west of Sirus), Betelgeuse of OrionÕs armpit on his sword wielding side (above Rigel), and Procyon of Canus Major (above & east of Sirus). Then, as it becomes a bit darker, Mercury is next to pop into view low along the western horizon along with Saturn who is east of Venus and higher along the Ecliptic above Betelgeuse. Mars is the dimmest visible planet right now and therefore last to pop into view. DonÕt confuse him with Aldebaran of Taurus who becomes visible first and has a reddish hue. Mars lies next to Aldebaran and is more in line with Venus. If you attempt to trace a line from Venus to Saturn, you will run through Mars; Aldebaran is lower than this line. Around this time, the sky begins to become populated with more and more stars becoming visible as twilight turns into night. Remember that you can always tell a planet from a star because a planet wonÕt twinkle. Stars do because they exchange gasses at their core though nuclear fusion and planets donÕt because their atmosphere reflects the light of the Sun.

At the onset of the month Mercury is traveling over 15 degrees east of the Sun and is therefore visible for over an hour after the Sun sets. On the 6th he stations retrograde at 4:28 p.m. EDT. This means from our geocentric point of view he is stopping to head west and move toward the Sun who is moving east. Therefore, he will only be visible for another couple days before he falls under the SunÕs beams. The pair reach inferior conjunction on the 16th at 9:05 p.m. EDT. This means that Mercury is passing between the Earth and Sun. This always signifies a retrograde period. The inferior conjunction of Mercury (and Venus) is always the middle of the retrograde period. Mercury stations direct on the 30th at 9:05 a.m. EDT. Then he will turn to resume his forward eastern trek through the zodiac. By this time the Sun will be far ahead and when he appears again, he will be west of the Sun as a morning star.

Venus and Mars both make conjunctions with Aldebaran this month as they journey through the constellation Taurus. You can use this fixed star to track their eastward motion. On the 1st Mars is a bit lower than Aldebaran. Looking a week later, youÕll see him above the alpha star of Taurus. Venus begins the month just below the star cluster of Pleiades, the seven sisters. By mid month she makes her way to conjunct Aldebaran. As the month draws on, you can watch Venus gain on Mars. She is on the inside track around the Sun. They are both headed to the edge of the constellation boundary and approaching the horns: Zeta Tauri (the lower, closer to Orion) and Elnath (the higher). By monthÕs end Mars is just past the horns and Venus is just below Elnath.

Saturn only moves about 3 degrees east this month through the constellation Gemini, so his motion is harder to detect. Jupiter spends the month retrograde and only moves about 3 degrees west through the constellation Leo during the month. Neither of them is crossing or nearing a very bright star, so you probably wonÕt detect a change in their position.

The Lyrid meteor shower peaks this month on the 21st. The radiants stem from the constellation Lyra the Harp. Lyra lies between Cygnus the Swan and Hercules.
ÉFor observers in the northern hemisphere, Lyra is fully above the north eastern horizon by 10:00 p.m. LDT, though better viewing occurs after midnight. As she gets higher you will notice more shooting stars. The usual number of meteors the Lyrids produce are 20 per hour. While this is not one of the most spectacular showers, it is the first good one after the winter lull in meteor activity, and it is the oldest recorded meteor shower. The Chinese recorded the Lyrids in 687 BC! The Lyrid meteor shower is compliments of the parent comet Thatcher C/1861 GI. As Earth orbits through the debris of ice and rock left behind by various comets, we experience meteor showers. Our atmosphere burns most of these up upon entry, which is what produces the shooting star affect.
ÉFor observers in the southern hemisphere, Lyra is fully above the northeastern horizon by 3:00 a.m. LDT. She stays fairly low to the horizon until sunrise. This will mean it is likely that you will only see a few meteors per hour. ÉSky maps of Lyra at midnight on April 21st at 10:00 p.m. for the northern hemisphere and at 3:00 a.m. for the southern hemisphere are available in the OCA Main Public Library to help you locate the shower.

As usual the Moon in her monthly journey through the zodiac will guide you to the visible planets. Viewers in the northern hemisphere will notice the Moon to the left of Jupiter on the 2nd in the constellation Leo. Since none of the visible planets are occupying the constellations between Virgo and Taurus (except Mercury in Aries will fall under the sunÕs beams by then) it is not until the later half of the month that she joins them. On the 22nd the Moon hangs below Venus and Mars in the western sky. By the 23rd she will pass them up and be headed toward Saturn. On the 24th she dances to the right of Saturn. On the 29th the Moon joins Jupiter again. She will be slightly above him in the night sky. A map of the Moon hanging below Venus and Mars on the 22nd is available in the OCA Main Public Library . This map also shows the nearby position of Saturn.

Viewers in the southern hemisphere will notice the Moon just below Jupiter as the sunset darkens the skies on the 2nd. By the evening of the 3rd she will have passed him up. She then journeys alone through the 2nd half of the zodiac, not conjuncting a visible planet until the 23rd when the Moon will set with Venus. On the 24th she dances to the right of Mars. On the 25th, the Moon hangs just below Saturn, passing him by the following night. On the 29th she returns to dance below Jupiter, passing him by the 30th. A sky map of the Moon with all four planets on the evening of the 23rd is available in the OCA Main Public Library .

The Full Moon occurs on the 5th at 7:03 a.m. EDT when the Moon opposes the Sun. Watch her set as this sun rises this morning. The Moon reaches perigee on the 7th at 10:25 p.m. EDT. This is her closest distance to Earth of 226,519 miles. The Moon perfects waning square to the Sun on the 11th at 11:46 p.m. EDT rendering a half illuminated Third Quarter phase. The Moon conjuncts the Sun on the 19th at 9:21 a.m. EDT, resulting in a New Moon. This is a partial Solar Eclipse, and it is visible in Antarctica, the southern half of Africa and Madagascar. The Moon reaches apogee, her farthest distance from Earth on the 23rd at 8:25 p.m. EDT. This distance is 251, 906 miles. The First Quarter Moon occurs on the 27th at 1:32 p.m. EDT when the Moon perfects waxing square to the Sun. Notice the half of her face that is lit is the half on the side of the Sun.

Happy stargazing!

Julene M. Johnson, NCGR-III
Media Director, OCA
Instructor, OCA
ONLINE College of Astrology
www.astrocollege.com
FIRST in Online Astrological Education