THE SOUTHWORTH PLANETARIUM
70 Falmouth Street  Portland, Maine 04103
(207) 780-4249   www.usm.maine.edu/southworth-planetarium
43.67° N 70.27° W
Founded January 1970
2022-2023: XCVIII
Sunrise: 5:01 a.m.
Sunset: 8:19 p.m.
Civil twilight begins: 4:25 a.m.
Civil twilight ends: 8:44 p.m.
Sun's host constellation: Taurus the Bull
Lunar phase: Waning gibbous (97% illuminated)
Moon rise: 10:38 a.m.
Moon set: 6:59 a.m. (6/6/2023)
Julian date: 2460100.29
"Once we accept our limits, we go beyond them."
-Albert Einstein

THE DAILY ASTRONOMER
Monday, June 5, 2023
June 2023 Night Sky Calendar  Part  I:

__________________________
*Happy 3rd Birthday, Miranda Beatrice!*
You're nothing but trouble and you get
away with almost everything.
_________________________


The true appeal  of astronomy is its lovely predictability.    Had I had
the wherewithal, not to mention the resources, I could have written this
calendar in the early 1980's.     Granted, considering my age at the time,
the end result would have been a bit of a mess, so it would have been
difficult to tell it apart from those composed in the present.   The modern
day sorcery of mathematical astronomy allows us to know the precise planet
locations and moon phases decades, even centuries and millennia in
advance.     The ability to forecast the sky so far in future distinguishes
astronomy from meteorology, where the conditions can change profoundly in
literally a blink.  (We here in New England recently went from the gorgeous
mid-90s to the average-looking mid-40s overnight.   According to the
meteorologists and their spinning dartboards, we'll be steeped in the
Stygian gloom until sometime this weekend.    Not at all miserable, of
course, but merely a reminder as to why the original European settlers
didn't name this region 'New Greece.')

Even though we're posting this article on the 5th, we want to start with
what has just occurred.   (To be fair, astronomy and meteorology are evenly
matched when it comes to explaining what happened yesterday.)

*SATURDAY, JUNE 3: VENUS AT DICHOTOMY*
Venus at what?!
When at dichotomy, Venus appears as a half-moon.  Just remember that when
Venus is at dichotomy, it is D-shaped.        We also recall that since
Venus is closer to the Sun than Earth, it exhibits a series of phases just
like the moon.*  Today, we can see half of Venus'  illuminated surface.

[image: Venus-UV-montage.jpg]
*[Venus' phases: *Note that when Venus is full it is on the far side of the
Sun and not visible to us.]   *Image credit: Sky and Telescope*


*SATURDAY, JUNE 3: FULL MOON*
The Honey Moon!   June's full moon is also known as the Strawberry Moon,
Mead Moon and, cruelly, the Heat Moon.   Depending on the full moon's date,
the June full moon will either be the last full moon of astronomical spring
or the first full moon of astronomical summer.    This year, June's full
moon occurs before the summer solstice and so serves as spring's final full
moon.

*SUNDAY, JUNE 4:   VENUS AT GREATEST EASTERN ELONGATION*
Venus is at its best.   Not only will our sister world reveal half of her
bright side, she will also stray as far from the Sun as possible during
this orbit.  Tonight, Venus will appear 45 degrees from the Sun.
Incidentally, the fact that Venus is 45 degrees from the Sun in our sky
while being at dichotomy is no coincidence.

*TUESDAY, JUNE 6: MOON AT PERIGEE*
We should always remember that our moon does not travel along a circular
orbit, but instead moves along a slightly elliptical path.  Consequently,
its distance from Earth changes continually.  During every orbit, the moon
reaches perigee, its point of least distance.  Approximately two weeks
later, it reaches apogee, its point of greatest distance.   Today, at the
precise moment of perigee, the moon will be 364,861 km from Earth.  Still a
formidable travel distance.

*FRIDAY, JUNE 9:  MOON NEAR SATURN*
Tonight one will see the waning gibbous moon (64% illuminated) passing
south of Saturn, the most distant of all the naked eye planets.    Both
bodies will rise by 1:00 a.m. within the Aquarius constellation.

*SATURDAY, JUNE 10: LAST QUARTER MOON*

*WEDNESDAY, JUNE 14: MOON NEAR JUPITER (BRONZE EVENT!)*
Jupiter has returned to the sky, albeit just before dawn.  One will see the
moon passing south of this gargantuan planet within the constellation Aries
the Ram.


*PART II tomorrow.*



*Galileo's observation of Venusian phases lent evidence in support of the
Copernican notion that the planets revolve around the Sun, not Earth.



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