OCTOBER  2010

OCTOBER STAR MAP | STARWATCH INDEX | MOON PHASE CALENDAR

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Current Moon Phase

737    OCTOBER 3, 2010:   Swimmers of the Sky

This week offers a good opportunity to become better acquainted with the autumn sky. The moon will be new on Thursday at 2:44 p.m., EDT, so it will provide no degradation to the heavens if the weather cooperates. If you are outside at 9:00 p.m., the first object that should greet you is brilliant star-like Jupiter about one third of the way up in the southeastern sky. It is the only saving grace for the celestial wanderers. In August it was planets galore, with Mercury, Venus, Mars, and Saturn visible after sundown in the west. Jupiter became prominent a few hours later in the southeast. Now Jove is the only holdout, but luckily for us, gracing the sky for most of the night. If you have a good southern exposure, look for a brilliant but lonely star in the SSE below and to Jupiter’s right. You’ll be viewing the brightest star of the constellation Piscis Austrinus, the Southern Fish, called Fomalhaut. Above and to Fomalhaut’s right is Capricornus the Sea Goat, and to the left, Aquarius the Water Bearer. If you’ve gotten the impression that this is the water district of the sky, you’re correct; but the seas are murky, and these star patterns are only easily visible from rural locales. That also includes Pisces the Fish which lies to the left of Aquarius and Cetus the Whale or Sea Monster, which is positioned farther south. See the online map included with this article. If you connect Fomalhaut and Jupiter you will be able to view Pegasus the Flying Horse jumping from the foam of the sea. Move upward along a straight line between these two objects and you will come to the left side of the Great Square of Pegasus, the body of the horse. At 9:00 p.m. the large square will look more like a baseball diamond because of its angle to the horizon. All of the luminaries of the Great Square are as bright as the stars of the Big Dipper, making Pegasus the only easily recognized pattern of the water group.

Water Constellations of Autumn...

738    OCTOBER 10, 2010:   Low Hanging Moon

The moon is well past its new phase, heading towards first quarter on Thursday at 3:39 p.m., EDT. If you have been looking for the moon, you should have noticed that it is very low and still not dominating the evening sky. During the several months surrounding the autumnal equinox, the moon is essentially a horizon hugger, hanging low in the sky throughout much of the first half of its phase cycle. Just the opposite is true at the time of the vernal equinox (spring), when the moon after its new phase shoots up into the evening sky like a rocket. Currently, the sun is headed deeper into the southern sky, towards its winter solstice position which will be occurring shortly after darkness on December 21, EST. The moon orbits the Earth at a five degree tilt to the plane of Earth’s orbit, the ecliptic, which is also the path which the sun follows in its yearly course around the heavens. That place, where the lowest sun will be located about two and a half months into the future, is the same area of the sky where the moon is currently found when it is near first quarter. So the moon must naturally be positioned low in the evening sky around this time of the year. There is one other hitch to creating our exceptionally low moon which is currently happening at the new phase. That five degree tilt of the moon’s path to the orbital plane of the Earth, almost always places the moon either above or below the ecliptic. If the moon is well below the ecliptic at new phase, as it is now, and the ecliptic is near its shallowest angle to the horizon (shallowest angle occurs on the autumnal equinox), then the daily orbital motion of the moon allows it to gain only a small amount of altitude, and it must remain very low in the sky. This same phenomenon is responsible for the harvest (full) moon rising at nearly the same time for several evenings centered on the fall equinox. Good low lunar observing this week…

739    OCTOBER 17, 2010:   Bad Moon Rising

During early October we have had some spectacularly vivid and sunny days along the East Coast. My wife and I call these Indian summer weather patterns “Santa Fe days,” where the air is mild and the sky appears a bright but saturated turquoise blue right down to the horizon. It was a wonderful time to dust off the telescope in my study and view Comet 103P/Hartley 2. Although this interloper was predicted to reach naked eye visibility, its very diffuse snowball-like nature has made it difficult to spot, even with large, light-grabbing binoculars. Hartley 2 looked like a small, circular exhalation among the stars on October 10 when viewed through my short focal length Newtonian with an 8-inch mirror. Hartley 2 reaches a distance of only 11 million miles from Earth on October 20, when it should be at its brightest, but what light it is creating will be completely washed out by the bright moon. Luna is full on the evening of the 22nd at 9:37 p.m. EDT. Another event which will fall victim to a nearly full moon is the Orionid Meteor Shower which peaks during the morning of October 21. Normally, 10-20 meteors can be seen each hour on the maximum morning if the moon is not present, but this year hourly rates will be depressed to 1-3 meteors. On the brighter side, a bad Orionid year sets the stage for a great Taurid Meteor Shower culmination. Taurids fly between September 25 and November 25 reaching a broad maximum between the dates of November 5-12. The moon is new on the fifth and just shy of first quarter on the twelfth. Although Taurid rates will be under 10 events per hour, these meteors are very distinctive, burning in slowly, sometimes lasting for durations of several seconds, as they sputter along their tracks. Taurids, in addition, can be very bright, producing a much higher than normal number of fireballs as they ablate in Earth’s atmosphere. Good sky watching!

740    OCTOBER 24, 2010:   All Hallows’ Eve

Death for most of us does not carry much appeal, yet each year at the very end of October we celebrate Halloween, a sort of “nose thumbing” to our successful efforts in eluding the Grim Reaper for one more year. All Hallows’ Eve, October 31, has its roots steeped in astronomy, just like Groundhog Day, February 2, and May Day, May 1. They fall on what are called cross-quarter days, approximately at the midpoints between the four seasonal markers of the sun: winter solstice (low sun), vernal equinox (mid-sun position), summer solstice (high sun), and autumnal equinox (mid-sun again). If you think about it, the cross-quarter day of October 31 is an apt time to celebrate death. The comfortable period of warmth and light is well beyond us. Our focus upon darkness and the cold of an encroaching winter overwhelms our psychics as the sun becomes lower in our noontime sky and rises later and sets earlier each day. Leave it to the pastoral Celts to have envisioned the harvest festival, Samhain (sa-win), meaning summer’s end and the Gaels (also Celts) of present-day Ireland and southwest Scotland to add a touch of the macabre. They believed the veil that separated the living and the dead thinned on Halloween permitting the creatures of the netherworld—souls of the dead, ghosts, fairies, and demons—to move freely about in our world. Sacrifices of animals and plants were made to the dead and bonfires were lit to help guide these ghouls along their way and keep them separated from the living. Offerings of food and drink were left outdoors to mollify and keep these creatures from entering homes. Later people dressed in costumes performed tricks and antics on others to receive a treat, thus ushering in our more modern ritual of “trick or treating.” The response of the Church to these popular frolics was to usher in All Saints’ Day on November 1 and All Souls’ Day on the 2nd.

741    OCTOBER 31, 2010:   It's about Time

The moment is almost upon us to change our clocks back to Standard Time. No, it won’t happen on Halloween. It’s Europe’s turn this week on the morning of October 31. We officially move our clocks back the following Sunday, November 7, by repeating the hours of 1-2 a.m. twice. That change puts us more in harmony with the sun, meaning that the sun reaches its highest point in the heavens, due south, around noontime each day rather than at 1 p.m. as it has been occurring since Sunday, March 14 when clocks were adjusted ahead to begin Daylight Saving Time. Remember it this way; fall back and spring ahead. We really don’t lose or gain any daylight; we simply put time in better synchronization to accommodate our waking hours. If you normally rise and shine around 6 a.m. on workdays, you’ve noticed over the past several months that it has been getting darker and darker each morning. Sunrise for 40 degrees north latitude is now happening about 7:30 a.m. By the winter solstice, sunrise would be closer to 8:20 a.m. when most of us should be in a fully functioning mode. Starting on the morning of November 7, the sunrise at 40 degrees north will occur at 6:30 a.m., and by the winter solstice it will be pushed back to 7:20 a.m. If we gain an hour in the morning, than we must lose an hour at sunset. On Halloween the sun goes down at 6 p.m. On November 1, that falls back to 5 p.m. bringing us closer to sunset around the evening commute. One of the main reasons always cited for wanting to give us some extra light in the morning deals with school safety. Most districts start their day between 7-8 a.m. and for rural districts this can mean an hour or more commuting on a school bus. Pickups can occur as early as 6 a.m. which would in some cases be occurring 2-1/2 hours before sunrise. Get ready for that extra hour of catch up sleep next week. It only happens once each year.