August 2013 Night Sky Calendar
We cringe when we hear some insensitive soul say "Well, can you believe it's already late summer?! My, how time flies!" First of all, time can't fly, only dilate. Secondly, and this is the important bit, August 1st does NOT mark late summer's commencement . Astronomically, August 1st represents the mid point between the summer solstice and autumnal equinox. It i is one of the four "cross quarter days," a mid-point day between one of the seasonal markers (See the August 1st entry) So, from an astronomical standpoint, today we have as much summer ahead of us as behind us. The meteorologists might insist that we're now in summer's last month, since they define summer as consisting of June, July and August only, but we astronomers are far more agreeable. Summer is merely in middle age: and, middle age is when the fun truly begins.
And, interestingly, the first week in August is also the warmest time of year statistically. (If one were to draw a graph of each day's average high temperature, one would describe a smooth, undulating curve that reaches its peak around August 2nd and its trough on February 2.)
THURSDAY, AUGUST 1 CROSS QUARTER DAY - LAMMAS
Each year has four cross quarter days; those nearly midway between successive seasonal markers. These dates are February 2 (Groundhog's Day) is the cross quarter day between the winter solstice and the vernal equinox; May 1 (May Day) is the CQ between the vernal equinox and the summer solstice; August 1 (Lammas) is the CQ between the summer solstice and the autumnal equinox; and October 31 (Samhain/Halloween) is the CQ between the autumnal equinox and winter solstice.
SATURDAY, AUGUST 3 MOON 4.0 DEGREES S OF JUPITER
This event is not a medal winner because we'll only see Jupiter and the waning crescent moon in the eastern pre-dawn sky. Yes, Jupiter returns, but its spending MID summer in the early morning sky; hardly convenient for those well balanced individuals who regard astronomy as a hobby.
TUESDAY, AUGUST 6 NEW MOON
Nothing to see here. Unless the moon passes in front of the Sun -an event called a "solar eclipse,"- the new moon isn't visible as it's aligned with the Sun. The lit half faces away from us.. In about two nights, one will see the thin sliver moon poised in the western early evening sky; the arc in the twilight. Tonight, a lunar cycle begins anew, but we'll have to wait a bit before we see the infant. Lunation cycle 1121 begins.
FRIDAY, AUGUST 9 (SILVER EVENT)* MOON 4.8 DEGREES SSW OF VENUS
Silver medal at the very least! Tonight, we'll see the waxing crescent moon and the brightest planet together in the early evening western sky. Observing these two worlds together is a high caloric eye treat and, moreover, this event is perfectly timed even for the faint hearted.
SATURDAY, AUGUST 10 SUN ENTERS LEO THE LION
We go through this ordeal every month. By "ordeal," we mean that we ramble on and on about how the Sun isn't actually moving through the thirteen constellations comprising the "ecliptic," or "zodiac." This annual solar migration is all illusory: caused by Earth's motion around the Sun. As our planet revolves around Sol, the latter seems to change position relative to the stars. And, at least in the short term, the Sun's location is consistent from year to year. The Sun appears to move into Leo the Lion this August, as it did last August and will again next August. We hasten, however, to point out that the Sun isn't actually moving. Then, we stop ourselves and remind the audience that the Sun DOES move through the galaxy. It just doesn't move through the constellations. (We told you this is an ordeal.) And, of course, we list these zodiacal constellations each month and, handily, capitalize the constellation the Sun just entered: 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; and Aquarius the Water Bearer.
MONDAY, AUGUST 12 (GOLD EVENT) PERSEID METEOR SHOWER PEAKS
Assuming the skies are clear, 2013 will be a wonderful year for the Perseids. Tonight, one could well see dozens or scores of meteors every hour as our furiously fast Earth plows through the densest part of Comet Swift-Tutttle's particle stream. A meteor shower occurs when our planet moves through a comet's path: consequently, Earth will capture many of the meteoroids gathered within this path. They descend through the atmosphere and excite the atoms within their vicinity: a process called "ablation." The electrons within the atoms ascend to higher energy levels. When they settle back to their previous lower energy "orbits" (that is a terrible word to use when referring to electrons) they emit the visible light we see as meteors.
The best time to observe a meteor shower is after midnight, when our part of the planet turns into the meteoroid stream. Even if you are not inclined to be out at that time, you can still see these meteors throughout the night. Another important point: the Perseid Meteor shower actually starts on July 17th and ends on August 24th. Passing through a vast cometary debris field is not merely an overnight jaunt. So, one can find Perseids here and there any time for the next few weeks. The name "Perseid Meteor Shower" tells you where to find them, as they appear to emanate from the high northern constellation Perseus the Warrior.
TUESDAY, AUGUST 13 (BRONZE EVENT) MOON 3.0 DEGREES SW OF SATURN
Saturn is drawing closer to its mid Autumn hiatus, so one will find the sixth world and the nearly quarter moon in the western evening sky. As Saturn is not nearly as bright as Venus, having the Moon nearby will help us find this distant planet. If the Moon-Venus encounter is a silver, we can ate least confer the bronze onto the Moon and Saturn.
WEDNESDAY, AUGUST 14 FIRST QUARTER MOON
SATURDAY, AUGUST 17 MARS AND JUPITER AND HELIOCENTRIC CONJUNCTION
What does this mean? Well, first, it means that we would see Mars pass Jupiter if we were observing it from the Sun. Since, of course, we're on Earth, we won't notice much of anything, except that Jupiter and Mars are now both pre-dawn planets. This Mars/Jupiter Heliocentiric Conjunction event is a fanatical, 18-carat geek event.
TUESDAY, AUGUST 20 FULL MOON
The Grain or the Green Corn moon. Also called the Late Summer Moon by deluded folks, August's Full moon looms over a world of warm moist soil and sultry air. Next month is the all famous Harvest Moon, although some will say the Harvest Moon will be in October this year. (We'll deal with that controversy in September.)
SATURDAY, AUGUST 24 MERCURY AT SUPERIOR CONJUNCTION
Another event for those who just can't get enough astronomy. Mercury passes along the other side of the Sun, so that, if we could actually see through the Sun, we'd spy Mercury behind it. "Superior Conjunction" is the alignment in which a planet moves to the Sun's far side. A planet is in "Inferior Conjunction" when it is between Earth and the Sun. All the other planets can be in superior conjunction, but only Mercury and Venus can be in inferior conjunction.
MONDAY, AUGUST 26 NEPTUNE AT OPPOSITION
Wonderful. Another one for the academics. Earth passes between the Sun and Neptune, the eighth planet from the Sun. Even though Neptune shine's brightest when at opposition, it is still more than six times dimmer than the dimmest naked eye star. The Sea God world lurks, appropriately enough, in the Seagoat constellation Aquarius. So, if you don't have a telescope, you will at least know where to look in order not to see it.
SATURDAY, AUGUST 31 MOON 4.5 DEGREES SOUTH OF JUPITER
Another Moon-Jupiter event. (The other reason we didn't give the first one a medal is because we'd be in a jam about what medal to assign this one.) The Moon is slightly larger during this Jupiter encounter than it was during the first one. The two worlds are also farther from the Sun this time (54 degrees as opposed to 33) and therefore they'll rise earlier. Also, Jupiter is slightly brighter now than it was at month's beginning. So, if you missed the first Jupiter-Moon gathering, you might have better luck finding this one. Of course, you'll still have to be looking after midnight.
MERCURY: Well, we call this one the "elusive planet" for a reason. World one is always close to the Sun and will peek just above the eastern pre-dawn horizon during early August. Then, it dives into the morning twilight, only to return to the evening sky around mid September. VERDICT: Even by Mercury's standards, it will be hard to see this month. If you HAVE to see it, venture out into the pre-dawn the first week of August. After that, give it a miss until mid September.
VENUS: Oh, Venus excites us into sleeplessness! After its prolonged absence -it left in late January and returned in late May- Venus promises to be a brilliant and gorgeous evening planet through the late summer (which starts Sept 15) and then through the autumn. Our sister world moves closer and shines brighter through the coming months. VERDICT: If you're out in the early evening, catch a glimpse of Venus! If you think of it, you might want to compare its brightness now to how it will appear in November.
MARS: Ok, well, after carrying on sycophantically about the goddess Venus, it would be untoward of us to simply mention Mars in passing, as though it were some unsightly superior planet we found splattered on our shoes' underside. The fourth world lurks ominously in the early morning sky. Fainter than all the other night sky planets, Mars appears as a ruddy red "star" within Gemini the Twins: a northeastern wee-hours sky sight. VERDICT: Even though Mars grows gradually brighter throughout the year, it will remain the faintest naked eye planet for the rest of 2013. A perfect sight for those who seek the sky's hidden jewels: such as the tarnished ruby in the post midnight sky.,
JUPITER: Venus is not the only planet that makes us giddy with anticipation. Jupiter, as well, promises to dazzle and delight as we proceed through late 2013. It rises after midnight this month, but will rise earlier each night through the year. And, it will also brighten dramatically. By December, it will be more than 2.5 times brighter than Sirius! VERDICT: It is not the easiest planet to find if you prefer to turn in at a decent hour. If you're out anyway in the deepest part of night, seek out Jupiter in the east. Otherwise, it will become all the easier to find as we stumble into autumn.
SATURN: (PICK PLANET!) Ok, DA, so you gush revoltingly about Jupiter and Venus, but then bestow the coveted Pick Planet prize onto Saturn? Expound. Well, Saturn has served us well this summer and remains a prominent sight in the early evening. Though we'll lose it within a couple months, it is still an easy planet to find. Also, we wanted to offer a tribute to it for what it has been. Besides, this is the last month this year when we won't be crowning either Venus or Jupiter or Venus. VERDICT: Seek Saturn this evening before midnight. You can use the two bright stars south of the Big Dipper's handle -Arcturus and Spica- to guide you toward it. Saturn is not visible between mid October and late November, so seize this opportunity to see world six.
PLANETS IN ORDER OF BRIGHTNESS THIS MONTH
VENUS - JUPITER - MERCURY - SATURN - MARS
*For those who just entered the classroom, the DA posts a monthly night sky calendar. Each month, for reasons we haven't actually fathomed ourselves, we confer "medals" onto the month's three most spectacular events. Of course, it's all subjective.