THE USM SOUTHWORTH PLANETARIUM

70 Falmouth Street Portland, Maine 04103

43.6667° N 70.2667° W
Altitude: 10 feet below sea level

Founded January 1970

Julian date: 2458392.35

2018-19: XX

"Would the primatologist who left the orangutans at Met Life Stadium please come collect them? They're beating the Jets 21 - 0."

THE DAILY ASTRONOMER

Monday, October 1, 2018

Week 5 Night Sky Calendar

October 1 - 7, 2018

Notice how every single date in the calendar causes us to be so astonished that we question reality. "Wow! October 1st already, can you believe it? It doesn't seem possible." Yes, October has arrived and September has just coughed out its last breath on the remote Aleutian island that nudges against the International Date Line. October is a strange month, not only because of the giggling ghouls and creepy creatures that will be laying siege to our peaceful domiciles like tsunamic outflows. October is strange because of its name: Although October is the tenth month of the year, its name means "eighth month," harkening back to the time when the calendar year didn't start in January. Even though we've been commemorating the year's birth on January 1st for quite awhile now, October is still called October. Note that the last four months of the year are so named, or, mis-named - September (7th month), November (9th month) and December (10th month.) All of these are quite boring month names, actually, unlike January, named for Janus, the two faced god of beginnings and endings,or August, named for the first Roman Emperor Augustus Caesar.

Calendars are, of course, human constructs. Earth is merely flowing through the space-time continuum in blind obedience to physical law. The seasonal shifts from sultry and sublime to frozen and ghastly are also just applied physics. We imposed a calendar to make sense of these transitions and to help us with those particularly human endeavors such as sowing and reaping. Even though precious few of us are now engaged in the extremely under appreciated agriculture field, we've retained the calendar as it is so useful for our day planners and in the preparation of monthly reports.

Earth just keeps moving continuously along the path it has tread for billions of years.

TUESDAY, OCTOBER 2: LAST QUARTER MOON

THURSDAY, OCTOBER 4: VENUS STATIONARY

If Earth is continuously moving (refer to the pointless introductory paragraphs), so, too, are the other planets. Venus never stops. From our moving perspective, however, Venus does sometimes appear to halt in its orbit before moving in the opposite direction. To understand the causes of this illusion, we should remember that we're watching Venus from an external vantage point. We watch it as NASCAR spectators watch cars speeding around a track. When a car reaches either end of the track, it won't move in a transverse way for a moment as it either moves toward or away from the spectators before changing directions. The same effect occurs when Venus and the other inferior planet, Mercury. Venus isn't stopping. It just seems to because we're on a more distant world moving around it.

FRIDAY, OCTOBER 5: MOON AT PERIGEE

The moon's distance from Earth is not constant because the moon travels along an ellipse, an "oval shape." Consequently, the moon will reach a point of greatest distance, apogee, and then another at least distance, perigee. When the moon reaches perigee around the same time it is full, we experience a "Super moon." The moon is currently passing through the waning crescent phase (16% illuminated) and so won't exactly be a super moon today. At the moment it reaches perigee, the moon will be 366,292 kilometers from Earth.

PLANET WATCH

MERCURY Mercury returns to the evening sky but, like a spoiled movie star who condescends to make a fleeting cameo appearance only after his exasperated lawyer explains the definition of 'contract clause,' Mercury is not going to remain in our sight for long. VERDICT: If you're poised on a mountain summit admiring the fading dusk, you might want to seek out Mercury this week. All sea level skywatchers might want to give it a miss.

VENUS will be exiting stage west by mid month. Venus is still the brilliant beacon in the western evening sky, but doesn't remain in our sky for long. By mid month our sister planet will sink out of sight. However, flighty Aphrodite will quickly re emerge into the eastern pre-dawn sky by November. VERDICT: Easier to find than Mercury, but you will still need an unobstructed western horizon to find it.

MARS: Fame is a fickle thing. Mars dazzled and delighted this summer during its perihelic opposition. The fourth world was quite a spectacle: brighter than all planets, save Venus. Its ruddy red color intensified to brilliant crimson and it commanded the admiration of millions. Now that Mars is moving away from Earth, it is growing dimmer and is attracting less attention. Yet, it remains visible in the sky throughout the evening and is still brighter than most stars. VERDICT: Mars is still easy to see, especially as it loiters in our sky for awhile.

JUPITER: (PICK PLANET) Jupiter is a western evening planet that is now setting slightly less than two hours after sunset. It is now the second brightest planet. VERDICT: One has to strain to find Venus and Mercury. Provided you're out early enough, you'll have no trouble spying Jupiter above the western horizon.

SATURN: Poor Saturn! It is the dimmest of the visible planets. Of course, being 898 million miles from Earth, Saturn has a distance disadvantage. At the moment, Saturn is slightly brighter than Betelgeuse, the red super giant star in Orion. VERDICT: Saturn might not dazzle, but at least it loiters about for awhile. See it set before 11:00 p.m.