THE SOUTHWORTH PLANETARIUM
70 Falmouth Street Portland, Maine 04103
(207) 780-4249 usm.maine.edu/planet
43.6667° N 70.2667° W
Founded January 1970
2022-2023: XXI
Sunrise: 6:36 a.m.
Sunset: 6:26 p.m.
Civil twilight ends: 6:54 p.m.
Sun's host constellation: Virgo the Maiden
Moon phase: Waxing crescent (15% illuminated)
Moonrise: 10:45 a.m.
Moonset: 8:21 p.m.
Julian date: 2459852.21
"Perhaps I am stronger than I think."
-Thomas Merton
THE DAILY ASTRONOMER Thursday, September 29, 2022
Two Red Worlds
______________________________________
Happy Belated Birthday to Diane H in Saugus!
A spirit whose vibrancy resists all diminishment
throughout the years.
_____________________________________
All right!
Today we start at 4:30 a.m.
Sheets off. Clothes on. Shoes tied. Arms stretched. Teeth brushed. Jacket
grabbed. Door opened. Breath cloud seen (sigh). Steps taken. Joggers
dodged. Headlights avoided. Phantoms retiring. Forest fringe shadowed.
Eastern sky grey. Meadow found. Center reached. Body down. Legs crossed.
Arm outstretched. Coffee forgotten. Meadow fled. Joggers outrun. Phantoms
frightened. Horns blared. Steps swift. Door slammed. House awakened. Curses
shouted. Thermos prepared. House again slept. Door slammed. Steps rapid.
Meadow reached. Breath strained. Body collapsed. Legs entangled. Arm
outstretched. Thermos opened. Hands spasmed. Contents spilled. Sky
brightening. Motorists passed. Birds flipped. Head tilted. Eyes up. Sky
unbounded. Night dissolving.....and now astronomy begins.
And, when you are casting your admiring eye up to the heavens before
twilight's onset, you will behold two beautiful red worlds high in the
south. Betelgeuse, the lower and dimmer of the two, marks Orion's eastern
shoulder. The higher and brighter world, Mars, is the fourth planet from
the Sun. Refer to image below, courtesy of Earthsky.org
[image: 2022-Sep-Mars-Orion-e1660676783399.jpg]
We now have the golden opportunity to observe two distinctly crimson orbs
adorning the heavens. Although most stars exhibit a non-descript whitish
hue, the night sky -indeed, the Universe- is alive with color. However,
in most instances the stars shine at such low light levels that we can
barely perceive these colorations. When Mars is at a great distance,
its light, too, seems indistinct. Now that it is drawing closer to Earth,
the fiery sheen of its rust-colored surface is beautifully apparent.
While these two red worlds look similar, they could scarcely be more
different. The first difference relates to distance. Presently, Mars is
74 million miles from Earth and will be moving ever closer until its
reaches its minimum distance of 51.5 million miles in early December.
Betelgeuse's distance is approximately 560 light years. To put this
value into context, 74 million miles equals 49 light minutes! If Mars is
our neighbor, Betelgeuse resides on another planet. The second difference
pertains to size. In terms of volume, Mars is about 15% the size
of Earth and our planet, if hollowed out, could accommodate about 5.5
Mars-sized spheres. As for Betelgeuse: Well, 1.2 million Earths could fit
inside the Sun.* One hundred and sixty million Suns could fit inside
Betelgeuse!** If our math is correct, one could therefore toss 1.05
quadrillion (1,052,000,000,000,000) Mars sized spheres into Betelgeuse.
These two factors illustrate how adept the night sky is at concealing depth
and size. From our perspective, Betelgeuse and Mars appear to be of
comparable size and distance. In fact, at magnitude -0.6, Mars shines
nearly three times brighter than its stellar companion and so seems to the
grander of the two: a convincing illusion, indeed.
Venture outside in the early morning and behold the two ember eyes of the
ancient dragon regarding you sternly: a reminder that even after Helios'
chariot ascends in the east, the mystical realm of the celestial might wink
out for a bit, but never fades away.
*To give you an idea about this number: 1.2 million m+m candies weighs
about 126,750 pounds.
**As it is a variable star, Betelgeuse's volume does vary. We're using an
average.
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