Sky watching this month brings quite a few observational experiences. In addition to viewing all the naked eye planets, there are 2 comets to watch for, a total lunar eclipse, an occultation of Venus by the Moon and a meteor shower.
As twilight begins to darken the evening sky in May, Venus, Mars, Saturn and Jupiter all pop into view. Venus, Mars and Saturn lie close to each other in the western sky. Jupiter will be nearly due South with the Moon to the east. Venus reaches her greatest brilliancy at 4:00 a.m. EDT on the 2nd and outshines them all. Jupiter is the next brightest, though the most brilliant Venus outshines him by 2.5 magnitudes. Saturn and Mars pale considerably in comparison. Venus shines almost 4 apparent magnitudes brighter than Saturn which outshines Mars by a little over a full magnitude. A difference of 5 magnitudes between two objects means one is 100 times brighter than the other. Possessing an apparent magnitude (brightness as observed from Earth) 5 times greater than Mars, Venus appears 100 times brighter than neighboring Mars.
The apparent magnitude scale originated with Hipparchus in 120 B.C. when he gave first rank to the brightest stars that became visible first and sixth rank to the dimmest seen by the naked eye. Ptolemy kept with this system as he added stars in ÒAlmagestÓ. Modern science kept with it as well. With the aid of telescopes we can catalogue very dim stars of 22nd magnitudes. The Hubble has allowed us to catalogue stars of the 30th magnitude. (Absolute magnitude of stars accounts for the actual brightness of a star factoring its own energy output among other things and is determined by a measure as if all stars were ten parsecs from Earth or 32.6 light years away. One parsec being 3.26 light years away because that is how far an object has to be to make a one second arc of shift in parallax as the earth travels around the Sun.)
May 4th boasts three celestial events: a lunar eclipse, the peak of the Eta Aquarids and the station of Jupiter. At 4:33 p.m. EDT the Full Moon results in a total lunar eclipse. From beginning to end, when the Moon enters and leaves the penumbra, the eclipse lasts from 5:51 p.m. GMT to 11:09 p.m. GMT. Totality occurs between 7:52 p.m. GMT and 9:08 p.m. GMT. Thus observers in the eastern hemisphere will be able to witness 76 minutes of totality. The beginning of the eclipse is visible from all but the northwestern part of Africa to all but the westernmost of Europe, spanning Asia, Indonesia, Australia, New Zealand and most of Antarctica. Moonrise occurs during totality in Ireland, Scotland and South America. The end of the eclipse is visible in Africa, Europe, Antarctica, western Asia and Australia, and all but the northwest part of South America. Moonrise on the east coast of North America occurs just before 9:00 p.m. EDT as the sun sets; by then the eclipse is over.
The Eta Aquarids peak on the evening of May 4th. The radiant of this shower occurs in the constellation Aquarius near the star Eta Aquarii. This shower typically produces 10 meteors per hour in the northern hemisphere and 40 per hour in the favored southern hemisphere. However, the Full Moon on the same night will reduce this number. Eta Aquarids meteoroids hit EarthÕs atmosphere at a speed of roughly 66 kilometers a second. The resulting meteors shine as bright as 3rd magnitude stars. Viewers in Australia will find the radiants 30 degrees above the eastern horizon at 4:00 a.m. local time. Viewers in the United States will find the radiants about 15 degrees above the horizon at this time. This meteor shower is produced by its parent comet Halley. Earth passes close to the orbit of HalleyÕs Comet twice a year. The other meteor shower we get from HalleyÕs Comet is the Orionids in October.
Jupiter stations direct on May 4th at 11:07 p.m. EDT. Due to the slowing affect a station has, Jupiter will only move 1 degree this month. That coupled with the fact he is not near enough to a bright star, will keep us from being able to visually track his return to eastward motion against the fixed backdrop of the stars.
Mercury reaches greatest western elongation on the 14th at 5:00 p.m. EDT. This means he will be visible as a morning star. On May 16th a slender balsamic moon joins Mercury in the sky, making the dim planet easier to spot. Mercury will brighten as the month progresses, but is soon lost to the glow of dawn. Viewers in Australia and the southern hemisphere will have an easier time observing Mercury because he climbs higher into the pre-dawn sky than he does in the northern hemisphere. A sky map of the morning of May 16th for both hemispheres is available in the OCA Public Library.
On the 15th comets LINEAR (C/2002 T7) and NEAT (C/2001 Q4) appear the brightest. Both are visible to the naked eye but NEAT is going to be easier to locate. NEAT is the brighter shining at a 2nd magnitude. LINEAR is a 4th magnitude comet. NEAT peaks above the northern hemisphereÕs horizon on the evening of May 3rd. Southern hemisphere observers have been able to see this comet since mid April. On the evening of the 15 NEAT will reach his brightest magnitude and the tail will be the longest. To locate comet NEAT, look in the area of the sky between Regulus of Leo and Pollux of Gemini. It is very near the Behive Star Cluster (M44) on the 15th, a 4th magnitude star grouping in Cancer. Looking through a telescope you can tell how much dust a comet is carrying. If NEAT is carrying little dust, the comet will appear round and bluish. If it has a lot of dust it will be parabolic and white.
LINEAR is not as easy to observe in the northern hemisphere. It lies very low in the evening sky in mid May. Better, though still not great, viewing will be in June. Observers in the southern hemisphere will have better viewing conditions. The best chance to catch a glimpse of LINEAR is to watch the area of the sky near Sirius. On the 23rd LINEAR passes between Sirius and star cluster M41. Northern hemisphere observers can use June 4th as a reference for locating this comet as it passes below Alphard of Hydra low in the west-southwest sky. You will be able to follow Jupiter straight down to the horizon that day; the line you make will pass through Alphard, then LINEAR, and then end at the Horizon.
Both Neptune and Venus station retrograde on the 17th. The Neptune station occurs at 8:13 a.m. EDT followed by the Venus station at 6:28 p.m. EDT. Venus moves 5 degrees east from the beginning of May until her station. She moves almost 3 degrees west from her station to the end of May. Therefore we can observe both her direct and retrograde movements this month.
Venus, Mars and Saturn traveling close to each other along the Ecliptic provide an excellent opportunity to watch their movement in relation to each other as well as the fixed stars. This is a nice line-up to watch throughout the month. On May 1st Venus lies just under Elnath, one of TaurusÕ horns. Mars lies slightly higher and west between the stars of Taurus and Gemini. Saturn lies in the constellation Gemini between CastorÕs feet and knees. Mebsuta, CastorÕs knee, is a good fixed star to watch SaturnÕs movement against. On the 6th Mars is noticeably in the constellation Gemini aligning next to CastorÕs left foot, 1 Geminorum, and Venus is noticeably passing Elnath. By the evening of the 17th, Mars will gain considerably on Saturn; both planets will be around the knees of the twins. This same night Venus will stop between the fixed star portion of both constellations to later begin her westward motion back through the horns of the bull. Mars nears Saturn on the 21st. The conjunction occurs on the 24th near the fixed star Mebsuta. Venus will then return to lie next to Elnath again. Mars continues to pass up Saturn and by May 31st Mars will be farther east in the constellation Gemini than Saturn, who will still be near Mebsuta.
At the beginning of the month in the northern hemisphere, Venus sets around 11:45 p.m. local time followed by Mars around midnight and Saturn around 12:45. Jupiter sets around 4:00 a.m. By midmonth, Venus sets 11:00 p.m. followed by Mars at 11:45 p.m. and Saturn around midnight. Jupiter sets around 3:15 a.m. By the 31st, Venus sets around 9:30 followed by Saturn around 11:00 p.m. and Mars around 11:15 p.m. Jupiter sets around 2:15 a.m. The end of the month will find Venus fading into the sunset thus ending her evening appearance.
At the beginning of the month in the southern hemisphere, Venus sets around 8:15 p.m. local time followed by Mars around 9:00 p.m. and Saturn around 10:00 p.m. Jupiter sets around 3:00 a.m. By midmonth Venus sets around 7:45 p.m. followed by Mars at 8:45 and Saturn around 9:15 p.m. Jupiter sets around 2:00 a.m. By monthÕs end Venus, setting around 6:45 a.m., will be lost in the sunset and ending her evening appearance. Saturn sets around 8:15 p.m. followed by Mars around 8:30 p.m. Jupiter sets around 1:00 a.m.
The Moon, as usual, will be your guide to help locating the planets. She makes no conjunctions with the visible planets until the 16th. The Moon nears Earth at a distance of 223,576 miles on May 6th. Perigee is reached at 12:32 a.m. EDT. The Third Quarter Moon occurs at 7:04 a.m. EDT on the 11th. The Moon dances with Mercury on the morning of the 16th. Observers in the northern hemisphere can spot the Mercury just below a slender balsamic moon on the 16th and just above the Moon on the morning of the 17th. Mercury will be very faint against the glow of dawn. Observers in the southern hemisphere can watch the Moon rise with Mercury around 6:00 a.m. on the morning of the 16th. Dawn will not encroach for about an hour providing a better opportunity for viewing Mercury than is possible in the northern hemisphere. The New Moon occurs on the 19th at 12:52 a.m. EDT.
On the 21st the Moon reaches her furthest distance from Earth of 252,441 miles. Apogee occurs at 8:00 a.m. EDT. At 8:13 a.m. the same day, the Moon occults Venus. This eclipse affect of Venus by the Moon is visible in northwest Africa, central Russia, northern India and most of Europe, excluding the northern Scandinavian region. On the evening of the 21st, observers in the United States and Canada will find the Moon between Venus and Mars. On the 22nd the Moon will be above Mars and Saturn in the evening sky. The Moon hangs below and west of Jupiter on the evening of the 26th, passing him by the 27th. A sky map of the evening of the 22nd around 10:00 p.m. for the northern hemisphere depicting the location of Venus, Moon, Mars, Saturn and Jupiter is available in the OCA Public Library.
On the evening of the 22nd, observers in Australia will find a sliver of a New Moon between Venus and Mars. On the 23rd a Crescent Moon will lie to the right of Mars and Saturn. The Moon joins Jupiter in the southern skies on the 27th when she will dance just below. The Moon passes Jupiter by the evening of the 28th. A sky map of the evening of the 22nd around 7:00 p.m. for the southern hemisphere is available in the OCA Public Library.
Happy stargazing!
Julene M. Johnson, NCGR-III
Media Director, OCA
Instructor, OCA
ONLINE College of Astrology www.astrocollege.com FIRST in Online Astrological Education
