March 2013 Night Sky Calendar
MARCH NIGHT SKY CALENDAR
Saturday, March 2, 2013
MOON 3.3 DEGREES SOUTH OF SATURN
After Jupiter's winter sky dominance slowly wanes, Saturn rises earlier each night and will soon become a prominent evening sky planet. (Read this sentence all over again in the Planet Watch section.) See World Six and its lunar companion tonight. They rise in the mid evening and remain visible for the rest of the night.
Monday, March 4, 2013
MERCURY AT INFERIOR CONJUNCTION
We deal with this issue every month because at least one planet always seems to move into some type of conjunction. The word "conjunction" means that two celestial bodies are along the same "arc of right ascension." (Right ascension is the celestial equivalent of longitude: whereas longitude measures a terrestrial object's distance from the prime meridian; right ascension measures a celestial object's angular distance from the vernal equinox point in Pisces.) Mercury moves into inferior conjunction with the Sun, so they occupy the same "line." Inferior refers to position: Mercury will pass between the Sun and Earth today. When Mercury is on the Sun's far side relative to Earth, it is said to be in "superior conjunction." As the Sun so close, Mercury is not visible.
Monday, March 4, 2013
LAST QUARTER MOON
Sunday, March 10, 2013
Time to disorder the Universe by shifting your clocks one hour ahead. Named "Daylight Savings Time" by Benjamin Franklin, who spitefully introduced the scheme to aggravate farmers, this time keeping change will remain in effect until Sunday, November 3, 2013.
Monday, March 11, 2013
Beginning of lunation cycle 1116.
A quick reminder about the new moon. The new moon is not visible as it is in conjunction with the Sun. (We can only "see" the new moon during a solar eclipse.) Don't bother finding the moon tonight. Look for a thin sliver moon low in the western early evening sky by Wednesday night. (It will be exceedingly difficult to see on Tuesday night.)
Monday, March 11, 2013
SUN ENTERS PISCES THE FISH
And, yes, we deal with the Sun's constellation house each month, as well. The Sun appears to move through thirteen different constellations each year. This progression results from Earth's revolution around the Sun. As our planet moves around the parent star, the latter's position relative to the background stars changes. Today, the Sun "enters" Pisces the Fish, the constellation it occupies on the vernal equinox: first day of spring. The thirteen constellations comprising this retinue are: PISCES THE FISH; Aries the Ram; Taurus the Bull; Gemini the Twins; Cancer the Crab; Leo the Lion; Virgo the Maiden; Libra the Scales; Scorpius the Scorpion; Ophiuchus the Serpent Charmer; Sagittarius the Archer; Capricornus the Seagoat; Aquarius the Water Bearer;
Saturday, March 16, 2013
MARS AT HELIOCENTRIC CONJUNCTION WITH URANUS
Why mention this event and what does it mean? Well, first, we truly neglect Uranus, Neptune and Pluto, as none of them are visible to the unaided eye.* Secondly, including this event gives us an opportunity to discuss another type of conjunction: "heliocentric conjunction" refers to a configuration in which two planets are "lined up" relative to the Sun. Were an observer to stand on Sol and observe the solar system, one would see Mars and Uranus along the same sight line.
Sunday, March 17, 2013
MOON 1.5 DEGREES SOUTH OF JUPITER
No, we will not designate this appulse as the month's pick event. We seem to confer that distinction on the Moon-Jupiter gathering far too often. One will find Jupiter and the waxing crescent moon together in the western evening sky. Beautiful pairing of Moon and planet.
Tuesday, March 19, 2013
FIRST QUARTER MOON
Wednesday, March 20, 2013 (PICK EVENT!)
Why not select Spring's first day as the pick event! After all, astronomically, this protracted, intolerably messy and bitterly cold winter yields to the gentler, warmer season of re-birth and beautiful Sun. Though the meteorologists declared that spring commenced on the 1st, we astronomers had to wait until the equinox. The Sun continues to climb; the nights shorten; and we rejoice at the promise of heat and light and flourishing crops. Astronomically, the Sun has "crossed" the celestial equator and will ascend above it until the summer solstice. Any object north of the celestial equator -which is just the projection of Earth's equator onto the sky- remains above the horizon for more than 12 hours. The higher the celestial object's altitude relative to the celestial equator, the greater its duration of visibility. We'll see the Sun above the horizons for twelve hours or more each day until September. For that reason alone, the Vernal Equinox deserves the honor of the month's pick event.
Friday, March 22, 2013
MARS 39" N OF URANUS
Wait? These two planets again? Well, yes, we include another "academic event," so called as it is not a visible phenomenon, at least not to use Mars will be within 39 arc seconds of Uranus. That is the closest planetary appulse between 1990 and 2020. Were we able to witness this close approach, this event would have easily been the pick of the month. Unfortunately, both planets are too close to the Sun for us to see. However, as it represents the closest appulse of two worlds within thirty years, it deserves inclusion. (Quick note about arc-seconds: a circle contains 360 degrees; one degree contains 60 arc minutes; one arc minute consists of 60 arc-seconds. The full moon's angular diameter is approximately one half a degree. one arc-second is 1/1800 of the full moon's "width." These two planets will indeed appear extremely close to one another. Too bad we can't see them.
Wednesday, March 27, 2013
Thursday, March 28, 2013
MOON 0.9 DEGREES ESE OF SPICA
Spica is Virgo the Maiden's brightest star. Tonight, we'll see the waning gibbous moon within a degree of it. Were we in some parts of Oceania, we would actually observe an occultation. Spica would appear to move directly "behind" the Moon. Occultations are amazing events because one can actually watch the occulted body "snap" off as the moon's limb moves in front of it. The moon lacks an atmosphere, so such blocked objects vanish immediately. If the moon had an envelope of gases on its surface, an occulted star or planet would disappear gradually.
Thursday, March 28, 2013
VENUS IN SUPERIOR SOLAR CONJUNCTION
Yet another chance to discuss "conjunction." Yes, we suspect the novelty has worn off by now. Venus will be at the far side of the Sun today and, of course, isn't visible. Only two planets, Mercury and Venus, can be in both inferior and superior solar conjunction.
Friday, March 29, 2013
MOON 3.4 DEGREES S OF SATURN
Another reason we didn't choose the Moon/Saturn approach as March's pick event is that it happens twice! We wouldn't have been able to select from the two events. The distance is just about the same (one wouldn't be able to tell the difference). Yes, the first approach is slightly closer, but during the second approach, Saturn is slightly brighter. The indecision was a torment, so we chose the equinox, instead. Find Saturn and the waning gibbous moon in the eastern mid to late evening and western early morning sky...again.
Sunday, March 31, 2013
Easter is an astronomical and an ecclesiastical event! Easter occurs on the Sunday after the full moon that is on or after the vernal equinox. This formula was established at the Council of Nicaea in 325 AD. The calculation allows Easter to occur anytime between March 22 and April 25th, inclusive. We could intoxicate ourselves with all the Easter date calculation intricacies: however, just a little fact - March Easters are isolated, meaning that one cannot have two consecutive years with March Easters. Also, the next March 22 Easter won't happen again until 2285; the next April 25th Easter is scheduled for 2038.
Sunday, March 31, 2013
MERCURY AT GREATEST WESTERN ELONGATION
Mercury will be 27.8 degrees from the Sun: close to the greatest angular distance it can ever attain from the Sun. When at western elongation, Mercury appears in the eastern pre-dawn sky. When at eastern elongation, Mercury is visible in the west.
World one is absent during the first half of March. Then, it emerges into the eastern morning sky with a vengeance. It climbs higher and grows brighter through the latter part of the month. At month's end, it surpasses Saturn in brightness, but remains dimmer than Jupiter. VERDICT: Mercury eludes at the beginning of March, but is worth a look toward month's end: especially the very end, when it is at its highest and brightest.
Not visible this month. VERDICT: This verdict will be a shock: don't bother. However, do note that we should let Venus sleep. When it returns in May, it will become a beautiful morning planet throughout the summer. By late autumn, it almost reaches its maximum possible brightness: 27 times brighter than Sirius! A sight that is worth the wait.
Not visible this month. VERDICT: Again, Mars admirers must pine for the next few months. Mars returns in June
JUPITER (Pick planet!)
Yeah, well, it is not as though it has much competition. Jupiter remains the only visible planet when the sky darkens. Saturn rises in the mid-evening; Venus and Mars are reposing in the perfumed gardens; and Mercury makes a spectacle of itself in the morning sky during March's second half. VERDICT: See brilliant Jupiter in the western evening sky and...blah blah..blah..you probably know the rest.
Jupiter descends in the west when Saturn rises in the east. The fifth sphere bows out around 2:00 a.m. at month's beginning, but Saturn is climbing higher. Saturn promises to grow in prominence until its opposition late next month. (A hint as to what April's pick planet will be.) VERDICT: A wonderful planet to behold: even if its not as bright as Jupiter. Saturn is a special treat if you have a telescope.
PLANETS IN ORDER OF BRIGHTNESS
Month's beginning: JUPITER - SATURN - MERCURY
Month's end: JUPITER - MERCURY - SATURN
*Uranus is, in theory, visible without a telescope. However, it is generally quite faint and one would have to know its precise location to find it.