From the Southworth Planetarium
“Anger feels like revenge; happiness is revenge”
THE DAILY ASTRONOMER
July 12, 2010
The Half July Sky Calendar
We know. Hardly anybody ever says, “Better late than never” and actually means it. The sentence “better late than never” is a distraction phrase, defined as one that will engage the mouth so it doesn’t say anything brutal or, worse, honest. So, we apologise. We perhaps should have sent this monthly sky calendar before about half of the month was over. Yet, we attribute this delay to other engagements, not to mention our notorious sense of irresponsibility.
So, since it’s so late, we’ll delve at once into our the July Sky Calendar, starting on July 11, of course.
Sunday, July 11: NEW MOON
Did you see the total solar eclipse? You might have observed it had you been in the South Pacific on July 11th. Otherwise, you will have missed the event entirely. Don’t fret, however. Other eclipses will follow. We’ll just have a wait a few years until we see a total solar eclipse here. (2024).
Monday, July 12: MOON 3.6 DEGREES S-S-W OF THE BEEHIVE CLUSTER
This is one of those AE’s (Academic Events.) Such events are noteworthy, but not easily observable. We include them for completeness, while admitting that most will miss this event as it occurs so close to the Sun. The July 11th event is another AE, since we couldn’t actually see it here.
Tuesday, July 13: MOON AT PERIGEE
Well, the third consecutive AE. Perigee is the closest point in the Moon’s orbit. While the Moon’s diameter changes slightly during its orbit, one can’t truly notice this change. The variable lunar distance affects tides, of course, so by measuring tides one can indirectly observe the Moon’s changing position. Yet, this is what is known in astronomy as a “stretch.”
Wednesday, July 14: MOON 5.5 DEGREES SSW OF VENUS
Finally, an event that is more visual than academic. Observers can enjoy the splendid vision of the crescent moon and brilliant Venus tonight in the western evening sky. The night sky’s two brightest sights share the early evening stage.
Thursday, July 15: MOON 5.6 DEGREES SSW OF MARS
Two Moon-planet encounters in the same number of nights. See the crescent moon close to Mars this evening. Mars is dim compared to Venus, but still quite easy to observe.
Friday, July 16: MOON 7.4 DEGREES SSW OF SATURN
Venus one night; Mars the next; and then Saturn the next. Yes, these planets are slowly approaching their August 8th “close encounter.” As the Moon travels across the sky, it visits each planet in turn. The 16th is Saturn’s night for a lunar fly-by.
Sunday, July 18: MOON AT FIRST QUARTER
Not much to add here.
Tuesday, July 20: SUN ENTERS CANCER THE CRAB
Or, as an astronomer would explain, Earth is on the far side of the Sun relative to the stars comprising the Cancer pattern. Therefore, it appears as though the Sun has “moved” into Cancer the Crab. This occupancy is a simple illusion of perspective.
Friday, July 23: JUPITER STATIONARY
One could dismiss this as an academic instead of visual event, I suppose, since one cannot “see” this event with one observation. Only if an observer tracked Jupiter against the stars could one notice that Jupiter will appear to stop in its eastward trek before beginning retrograde (westward) motion. So, whether or not this one is an AE depends on how closely one watches the planets.
Sunday, July 25: FULL MOON
The names assigned to the July Full Moon range from the prosaic to the fantastic. The Colonial Americans called it the “Summer Moon.” To the Dakota Sioux it was the “Moon of the Middle Summer.” Agriculture figured into the Cherokee name of “Ripe Corn Moon.” However, to the Chinese it is the “Hungry Ghost Moon.” According to Chinese legend, during the seventh lunar month, the souls of the recently departed emerged from their subterranean confines to rejoin the relatives they left. The spirits of those people whose relations neglected to perform the proper rituals, were condemned to wander the Earth aimlessly. During the seventh lunar month, many living souls offered food and money to these ghostly wanderers.
Tuesday, July 27: MERCURY 0.29 DEGREES SSW OF REGULUS
Both planet and star will be twenty-five degrees from the Sun. We mention this event because it is the closest appulse of a planet and 1st magnitude star. An “appulse” is a close approach of two celestial bodies.
Tuesday, July 27: MOON AT APOGEE
“Apogee” is the most distant point on a moon’s orbit. See July 13th for more information.
Friday, July 30: MOON 6.6 DEGREES NNW OF JUPITER
A splendid late evening/early morning event. See the giant planet close to the gibbous moon.
Saturday, July 31: MARS 1.8 DEGREES SSW OF SATURN
See Mars and Saturn close together for the next couple of weeks. Also, watch for Venus to join them.
PLANET WATCH
MERCURY: In one way, it is convenient that this sky calendar is so late. Mercury was too close to the Sun for observation early this month and only now can one find it low in the western evening sky. VERDICT: Better to wait until month’s end, but even then could prove elusive.
VENUS: Venus, always bright, will grow brighter through early autumn. Find it in the western evening sky all month. Apart from the Moon, it will be the first celestial object that appears after sunset. VERDICT: Always brilliant! Always eye-catching! Always beguiling! What’s not to adore? A beautiful sight for early evening observers.
MARS: As you might have realized, most of the action is in the western evening sky this month. Mars is part of the “western trio,” along with Venus and Saturn. Presently, Mars is slightly dimmer than Saturn, but they might appear of
equal brightness. Mars’ ruddy coloring makes it distinct. VERDICT: If you’re up admiring Venus, anyway, might as well find Mars.
JUPITER: Although it is displaced from the planetary party in the west, Jupiter is growing brighter and will reach opposition in September. Therefore, Jupiter promises to be a spectacular autumn and even winter sky sight. Now, it is still rising in the late evening, which is inconvenient for some observers. VERDICT: Jupiter is always worth a look, but if you don’t feel like going out of your way, don’t worry. Jupiter takes center stage soon, so you’ll have plenty of opportunities to see it throughout the next few months.
SATURN: Close to Mars and brighter than Mars, but only just. We like Saturn because it is often the first thing we envision when someone asks us to imagine an alien world. VERDICT: Though it is dimmer than Venus, Saturn is still a treat for the eye. Thus, it is our PICK PLANET of the month. One could easily choose any of the others, but Saturn will soon leave us for awhile, so we want to give it some more time with the crown. Which planet we’re going to choose next month is anybody’s guess.
