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
70 Falmouth Street Portland, Maine 04103
(207) 780-4249 usm.maine.edu/planet
43.6667° N 70.2667° W Founded January 1970
2022-2023: LXVI
Sunrise: 6:09a.m.
Sunset: 5:36 p.m.
Civil twilight begins: 5:41 a.m.
Civil twilight ends: 6:05 p.m.
Sun's host constellation: Aquarius
Moon phase: Waxing gibbous (99% illuminated)
Moonrise: 4:46 p.m.
Moonset: 6:31 a.m. (03/07/23)
Julian date: 2460010.29
"Gravity is a contributing factor in nearly 73 percent of all accidents involving falling objects." -Dave Barry
THE DAILY ASTRONOMER
Monday, March 6, 2023
March 2023 Night Sky Calendar Part III
FRIDAY, MARCH 17: MERCURY AT SUPERIOR CONJUNCTION
The first world, which, we should mention, whips around the Sun at the devil-may-care speed of about 107,000 miles per hour, reaches the far side of the Sun relative to our perspective today. We refer to this configuration as superior solar conjunction. When Mercury passes between the Sun and Earth it is said to be in inferior solar conjunction. (Mercury will next pass through inferior solar conjunction on May 1, 2023) Mercury will move into the western evening sky by the end of the month.
SUNDAY, MARCH 19: MOON NEAR SATURN
One will see the waning crescent moon (5% illuminated) just to the south of Saturn in the eastern pre-dawn sky. This thin crescent moon and giant planet will rise by 6:10 a.m., about half an hour before sunrise. Consequently, Saturn will remain visible briefly after it rises, so observers are advised to venture out between 6:10 - 6:30 a.m. to find it.
MONDAY, MARCH 20: VERNAL EQUINOX (PLATINUM EVENT!!!!)
After an interminably long, despair-inducing, sense-assaulting, flesh-freezing period of stygian gloom and Plutonian temperatures, the first day of astronomical spring has finally arrived, much to the glee and delight of the survivors.
To understand why the Sun appears to vacillate between a high and low point during the year, we need to view our planet from a position outside its orbit. Earth's axis is tilted relative to the vertical by 23.5 degrees. (See graphic below.) As the planet revolves around the Sun, the orientation of the Sun relative to the north and south poles is constantly changing. When Earth reaches the Summer (June) solstice, the north pole is aligned as close to the Sun as possible. Consequently, the Sun's altitude above the southern horizon is highest. Six months later, the North Pole is aligned away from the Sun as much as possible and the Sun's altitude is lowest. Conversely, in June, the south pole is pointed away from the Sun and in December, the south pole is aligned close to the Sun.
The revolving Earth. If Earth were not tilted on its axis, the Sun's altitude wouldn't change throughout the year. However, Earth's axis is tilted relative to the vertical by 23.5 degrees. As Earth revolves around its parent star., its poles shift alignments relative to the Sun. In the winter, the northern hemisphere points away from the Sun and in the summer, the northern hemisphere is directed toward the Sun. On both the vernal and autumnal equinoxes, neither pole is aligned toward the Sun, which shines directly on the equator. Image: National Weather Service
On the equinoxes, neither pole is aligned toward the Sun, which appears to shine directly on the equator. This date is called the equinox, from the Latin term "aequinoctium," meaning "equal night." Because Earth is neither uniformly dense nor perfectly spherical, the Sun doesn't fall on the planet evenly and we will not have twelve hours of daylight on the equinox.
The above image shows the Sun's path during the four seasonal transition days. The Sun follows the lowest path on the winter solstice; the middle path on both the vernal and autumnal equinoxes and the highest path on the summer solstice. Also, on the vernal and autumnal equinoxes, the Sun rises due east and sets due west.
TUESDAY, MARCH 21: NEW MOON
Beginning of lunation cycle 1240.
WEDNESDAY, MARCH 22: MOON NEAR JUPITER (BRONZE EVENT!)
Soon...VERY soon...after sunset one might see Jupiter close to the razor thin waxing crescent moon (2% illuminated) . At closest 'approach, Jupiter will appear to be 0.5 degrees away from the moon. However, from some regions of northern South America, observers will see a lunar occultation: the moon will move directly in front of Jupiter. Although we won't be able to watch the occultation, we can still see these two worlds appearing to come into close contact, provided that we go out soon after sunset. The moon and Jupiter will set just after 8 p.m.
FRIDAY, MARCH 24: MOON 0.1 DEGREES SOUTH OF VENUS (SILVER EVENT!!)
Although one might be hard pressed to see the Moon-Jupiter appulse, seeing the waxing crescent moon appearing to veer close to Venus will be a much easier sight to observe. An observer will see the waxing crescent moon (13% illuminated) south of Venus in the western evening sky. Venus will set by 10:00 p.m. and the moon will follow at 10:46 p.m.
TUESDAY, MARCH 28: MOON NEAR MARS
Find the red planet close to the first quarter moon tonight. Although Mars isn't particularly bright (2.5 times dimmer than Jupiter; 40 times dimmer than Venus), at least it remains above the horizon until 2 a.m. One will see the moon passing north of the fourth world this evening.
TUESDAY, MARCH 28: FIRST QUARTER MOON
PLANET WATCH
MERCURY:
This fast and furious world is difficult to observe until the very end of March, at which time it will peek up in the western evening sky. Although it will never be an easy sight, the first world proves particularly elusive for most of the month. VERDICT: Give Mercury a miss until late month and even then one will have to venture outside soon after sunset to spot the world against the fading western twilight
VENUS: PICK PLANET!
Early this month, Venus and Jupiter appeared to come within 0.5 degrees of each other. Like ships passing through the night, Jupiter will continue to descend toward the Sun while Venus moves farther away from it. VERDICT: One will experience little trouble finding Venus in the western sky this month. Just seek out the brilliant beacon poised high above the western horizon after sunset.
MARS
Locked within the horns of Taurus the Bull, the red planet has faded down to magnitude 0.5, still bright but not nearly as brilliant as it became during its opposition last December. One can look for Mars near Aldebaran, the orange star marking the bull's eye. The crimson hue of Mars strikes a pleasing contrast to Aldebaran's tangerine glow. VERDICT: Simply look high in the western evening sky to find the fourth world. It doesn't dazzle, but it does delight. Mars will remain visible in our evening sky until mid autumn, so one will have ample opportunity to find this world.
JUPITER
The largest planet has made quite a spectacle of itself in the western evening sky, but will soon vanish into the dusk. Jupiter passes into superior solar conjunction on April 11th. Although it will continue to outshine all the stars, save the Sun, Jupiter will become increasingly more difficult to observe throughout March. VERDICT: Best to go out earlier in the month to see Jupiter, which appears as a bright 'star' low in the western evening sky.
SATURN
Saturn passed into superior solar conjunction in mid-February (despite the DA's hiatus) and is only now emerging into the eastern pre-dawn sky. At magnitude 0.9, Saturn is the dimmest of the naked eye planets and, with the possible exception of Mercury, the most difficult to find. VERDICT: Don't go out of your way to find Saturn this month as it will be rising less than an hour before the Sun. Saturn will be much easier to find later this spring and summer, especially in August, when it reaches opposition.
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