October 2013 Night Sky Calendar
October's beginning always surprises us. Perhaps more so than any other month, October's commencement staggers the world. After all, September began a few days ago, ushering in a new school year. Whenever the fall term begins, we believe that a century will have to elapse until summer's much anticipated return. And, now, it's already October: the first of the three holiday months. Blink twice and we'll be preparing for Thanksgiving. Before you blink, however, we'll proceed through the October night sky highlights.
We're sorry that October's night sky calendar won't be as extensive as September's. We believe that we can tell you, for instance, that the Moon will be at the last quarter phase on October 26th without belaboring the point with a thousand-word aside. And, despite a certain individual's disdainful attitude, we'll resume our medal award for astronomy events and will confer the coveted crown on one of the planets.
Also, we'll neglect Comet ISON in this calendar, but will feature it prominently in November.
SATURDAY, OCTOBER 4
We think that they could have chosen another name for the new moon. New suggests shiny and fresh, like the appearance of a full moon. The new moon, however, isn't visible: the phase cycle starts anew as the Moon passes between Earth and the Sun. Within a couple days, one will see the thin crescent moon in the western evening sky.
Beginning of lunation cycle 1123.
MONDAY, OCTOBER 6
MOON 2.8 DEGREES NNE OF MERCURY
MOON 2.0 DEGREES SW OF SATURN (GOLD EVENT!!!)
Though we listed two different events, one can regard these as one event: Mercury, Saturn and the thin crescent moon are together in the western evening sky. If you are out soon after sunset, don't miss this gathering of two worlds and the crescent moon. Unfortunately, the moon is such a thin sliver and close to the Sun that the show will be over in th early evening.
TUESDAY, OCTOBER 7
MERCURY 5.0 DEGREES SSW OF SATURN
Tonight, one will see the most distant naked eye planet close to the first planet from the Sun. Though they're low in the western evening sky, Mercury and Saturn are both observable soon after dark. Mercury is about 1.5 times brighter than its companion.
WEDNESDAY, OCTOBER 9
MERCURY AT GREATEST EASTERN ELONGATION (25.3 DEGREES FROM THE SUN)
Mercury is visible in the western evening sky when it is at eastern elongation and visible in the eastern morning sky when at western elongation. Though Mercury won't be an easy sight this month, this is the best time to try to find Mercury.
FRIDAY, OCTOBER 11
FIRST QUARTER MOON
The first quarter phase, also called "quadrature," is the first 'half moon.' We see one half of the moon's illuminated region. It rises around noon and sets at midnight, although these times are not precise. We refer to the half moon as a 'quarter' because when it is at the first quarter phase, the Moon has completed one quarter of its orbit.
TUESDAY, OCTOBER 15
MARS 0.9 DEGREES NNE OF REGULUS
Leo has returned! Actually, Leo returned a few weeks ago, but each night rises slightly earlier. Regulus, its brightest star, appears to come within a degree of Mars, the ruddy red late night planet. They are almost equally bright (Regulus is slightly brighter) and visible well after midnight. If these objects were more prominent, or up earlier, this event might have earned a medal.
WEDNESDAY, OCTOBER 16
VENUS 1.5 DEGREES NNE OF ANTARES (SILVER EVENT)
This one gets the silver because we're seeing a star and planet so close to one another. Also, observing these two together helps us appreciate Venus' brilliance. Though Antares (magnitude 1,04) is the 17th brightest night sky star, it is still 130 times fainter than Venus (magnitude -4.3). While we'll soon lose Antares and its host constellation, Scorpius, to the evening twilight, Venus is rising higher and becoming more prominent,
FRIDAY, OCTOBER 18
Tonight, nobody will see a penumbral lunar eclipse. By which we mean, of course, that the full Moon will pass through Earth's outer shadow, called the "penumbra." Unlike an umbral eclipse, which is readily visible, a penumbral eclipse causes only a subtle shading: a faint obscuration that is exceedingly difficult to notice.
However, we can all see a full moon tonight! Remember the full moon is nine times brighter than a quarter moon. Even if you're far removed from city lights, you will be able to see your way clearly, under the full moon light.
MONDAY, OCTOBER 21
ORIONID METEOR SHOWER
We consider this yea to be quite unfavorable for this shower as the moon will obscure the viewing. Meteors occur when meteoroids enter the atmosphere, resulting in a excitation we perceive as a meteor, or streak of light. This evening, we're passing through the densest part of a debris trail cast behind by HALLEY'S COMET, the most famous of them all. Though we won't see Comet Halley again until 2061, we can see a few of its fragments disintegrate in our sky. Expect to see only a few meteors an hour, the number one would see on any given night, anyway. Best time to observe is after midnight.
FRIDAY, OCTOBER 25
MOON 5.0 DEGREES SOUTH OF JUPITER (BRONZE EVENT)
This event is a medal winner because one can observe the brilliant planet poised above the gibbous moon: a lovely spectacle. We only gave it the bronze because it rises in the late evening: not conveniently timed for most of us. However, tonight we encourage you to find it ascending in the eastern post-midnight sky.
SATURDAY, OCTOBER 26
LAST QUARTER MOON
Also known as "quadrature," the last quarter moon rises around midnight and sets around noontime. These times are not precise as the Moon's altitude constantly changes.
SUNDAY, OCTOBER 27
MOON 6.6 DEGREES SSW OF BEEHIVE STAR CLUSTER
The Beehive Star Cluster is Cancer the Crab's only prominent feature. This diffuse star cluster resembles a faint oval light patch. Tonight, see the waning crescent moon pass "below" it. As the Moon and cluster are more than six degrees apart, the Beehive will remain visible even though the Moon has just moved beyond th last quarter phase.
TUESDAY, OCTOBER 29
MOON 6.1 DEGREES SSW OF MARS
As Mars is the dimmest naked eye planet (see Planet Watch), having the Moon close by tonight will help you locate it. Mars is "above" the Moon and will appear as a distinct reddish star-like object. As the Moon will be in the waning crescent phase, its light won't obscure Mars much at all.
WEDNESDAY, OCTOBER 30
SUN ENTERS LIBRA
Libra is almost the 'forgotten' zodiac constellation. Not particularly bright, and low in our mid northern latitude skies, Libra bridges the gap separating Virgo the Maiden and Scorpius the Scorpion. And, as we already know, the Sun doesn't actually "enter" Libra. Instead, Earth revolves around the Sun, causing the Sun's apparent position through the sky to change. Today, the Sun appears to enter the Libra region and will remain there until November 23rd. The ecliptic (zodiac) sequence is as follows: LIBRA THE SCALES, Scorpius the Scorpion, Ophiuchus the Serpent Charmer, Sagittarius the Archer, Capricornus the Seagoat, Aquarius the Water Bearer, Pisces the Fish, Aries the Ram, Taurus the Bull, Gemini the Twins, Cancer the Crab, Leo the Lion, and Virgo the Maiden.
WEDNESDAY, OCTOBER 30
VENUS AT THEORETICAL DICHOTOMY.
Yes, this one sounds more like an Trinket event. All this means is that Venus will appear half illuminated from our perspective. Venus is never full because, as an inferior planet, it can never be at opposition. Most of the time, Venus appears as a crescent. Now, Venus is at a quarter phase...the increase in its exposed illuminated area is one factor responsible for its increasing brightness.
MERCURY: World one remains visible the first half of the month, and is best seen around October 9, the date of its greatest eastern elongation. After mid-month, however, it vanishes into the dusk. VERDICT: Not an easy sight -when is it ever?-, Mercury lurks low in the western evening sky. Seek it out until the 15th and then don't bother. It will return to the morning skies in November after passing through inferior conjunction November 1st.
VENUS (PICK PLANET!) As if you didn't know Venus would get the bejeweled diadem. Our sister planet shines brilliantly this month in the western evening. Venus climbs higher in the west as the planet moves closer to Earth. We'll watch it brighten throughout October and November. As spectacular as Venus is now, realize that it will be two and a half times brighter on December 1st than it is now. (Yes, we know who'll keep the crown the rest of 2013). VERDICT: Perfect time for Venus admirers. Observe it early evening in the western sky. One can even see it just after sunset. Finding it during the day is possible, but difficult. If you miss Venus tonight, you'll have ample opportunity to see it other nights.
MARS: Poor Mars. We dote on Venus and put it in pretty dresses while leaving Mars in front of the bedroom television away from the relatives. Mars does brighten throughout the month and ascends higher in the eastern early morning sky. Of course, it is the dimmest of the naked eye planets this month and rises after all the others, so it won't attract a great deal of attention. Nevertheless, Mars is about as bright as Bellatrix (Orion's western shoulder star) and distinctly red. VERDICT: If you're up before dawn, look for Mars in the eastern sky. It doesn't dazzle like Venus, but is still moderately bright easy to find in a dark sky.
JUPITER: We lost Jupiter in early summer and regained it in mid July. Ever since, the biggest world has steadily risen earlier each night. Now, at month's beginning, Jupiter is up at midnight. By late October, it rises around 10:00 p.m. Jupiter outshines all the night sky stars and every other planet save Venus. Jupiter continues to brighten for the rest of the year. VERDICT: A beautiful sight if you're up late at night. Best time to observe it is after midnight, preferably the pre-dawn, when it is high in the eastern sky.
SATURN: The sixth world has enjoyed a lovely run throughout the spring and summer. Now, however, we'll watch Saturn retreat backstage for a blissful and well deserved lie down. One can still observe Saturn low in the western early evening sky, but it won't linger long in our sight. VERDICT: If you MUST see Saturn, look at month's beginning. The sooner the better. By mid month, we bid adieu to Saturn until late November, when it emerges into the early pre-dawn sky.
The planetary order, from brightest to dimmest:
(Uranus, Neptune and Pluto are not visible to the unaided eye.)
VENUS - JUPITER - MERCURY - SATURN - MARS
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