By “Astro” Mark Laurin
Used with permission.
The night sky in March is different. It’s a feeling type of difference, and a celestial difference. March is a month of transition for the celestial dome overhead. Why? Enter the springtime sky. Most significant of this season is the vernal equinox, the transition from winter to summer, passing through spring. The returning Sun rides its ecliptic path noticeably higher in the daytime sky. Days grow longer, and the nights feel not so cold. (Dare I say this living in the mountains?)
The transition benefits the stargazer. Why? We can observe many of the outstanding gems of the winter sky without straining our necks to look up, and being outside at night is a bit less brutal. Moreover, these spectacular winter jewels are viewable earlier in the evening. Unfortunately, for those of us living in a world of daylight savings time, evening now arrives later in the day once we “spring forward.” It’s a fair tradeoff. This month there’s the spring equinox, a visiting comet, and achieving new heights, the winged god Mercury arrives. That’s right, our innermost planet gives us its best appearance of the year this month. Not bad, not bad at all. But first, the seasons go round and round.
The Vernal Equinox, March 19th
We have four seasons on Earth; winter, spring, summer, and autumn. These seasons divide our journey around the Sun and result from our planet’s angle to the Sun. To complicate things, the season in the northern hemisphere is the opposite of the season in the southern hemisphere. It’s that darn Earth angle to the Sun thing again. The Vernal Equinox is at 9:04 pm and is the astronomical beginning of the spring season in the northern hemisphere; and the beginning of autumn in the southern hemisphere. If you’re standing on the equator at the time of the spring equinox no matter where you are on Earth, the Sun will be directly overhead (assuming it happens in daylight hours) and day and night are approximately both 12-hours in duration. From this date forward the Earth tilts more towards the Sun in the northern hemisphere giving us more daylight hours, earlier dawns, and later sunsets. Oh yeah!
Comet 12P/Pons-Brooks, March 1st – 15th
Most often the events noted in this calendar are objects you can see without the aid of optics, you can observe them with your naked-eyes, and they are easy to find in the sky. An exception to this are comets. Hunting for comets steps up your observing skills and is worth the effort. This month is a prime opportunity to witness Comet 12P/Pons-Brooks once astronomical darkness is reached; about 90-minutes after sunset. Pons-Brook is a periodic comet discovered in 1812 and last visited the Earth in 1954. The comet is anticipated to be bright and visible early in the month.
To locate Comet 12P you first need to find the constellation Cassiopeia above the western horizon. By that time of night, the predominant W shape of the constellation’s five brightest stars are easy to locate. Next, use the right “v” of the W and the tip star (Schedar) as your pointer star and draw an imaginary angling line down towards the point at compass point west at the horizon. Then 2/3 of the length of this line down to the horizon and Schedar, you’ll see the fuzzy smudge of the Andromeda galaxy; it will be a sizable smudge and difficult to miss. Now continue this same line down towards the horizon and at 1/3 the distance between the Andromeda galaxy and the horizon is comet 12P/Pons-Brooks. Look for a smudge-like object similar to Andromeda, but smaller, with a distinct protrusion, which is the comet’s tail.
Conjunction of Jupiter and the Moon, March 13th
To begin, an astronomical conjunction is when two or more astronomical objects appear close to each other, to share the same spot in the night sky, so to speak. It’s all about our point-of-view. To us, the objects share the same right ascension, or ecliptic longitude. Basically, an “east-west” position in the sky. On the 13th, the delight in this conjunction between Jupiter and the Moon, is that the Moon is only a 3-day waxing crescent. Both objects are easy to find in the western sky at sunset. With the Moon being relatively dim that night to the upper right of Jupiter, grab your binoculars since you can observe Jupiter and its four Galilean moons (Callisto, Europa, Ganymede, Io) in the same field of view with the crescent Moon. The pair become visible in the southwestern sky around 7:21 pm as dusk fades to darkness. From that time the pair will fade, sinking towards the west and crossing the horizon at 11:11 pm.
Mercury High in the Sky and Far Away, March 24th
The Winged Roman and Greek God of commerce, communication, and travel, and tiny innermost planet of our solar system, Mercury takes celestial center stage on March 24th. On that day two distinct astronomical variables occur. First, Mercury achieves its greatest elongation away from the Sun in its orbit around the Sun. Second, Mercury’s inclined angle to the Sun places it a high 17 degrees above the western horizon in the evening sky. Get ready, you’ll have 45-minutes to view Mercury after sunset, before it falls below the western horizon and only for a few days. Plus, on the evening of the 24th, this swift and illusive planet is easier to find. Unfortunately, you’ll need binoculars to see Mercury as more than a tiny white-pinkish dot of light.
To find Mercury this night look to the western horizon as the Sun sets. From the point where the Sun crosses below the west, draw a line up to the only bright pinprick of light above the vanished Sun. That point is the planet Jupiter. Now scan your binoculars slowly in a narrow back and forth fashion on the midway point between Jupiter and the departed Sun. You are looking for a faint oyster pearl colored dot of light. You can distinguish it from surrounding stars as it is a dot of light with a more defined edge, or limb. Mercury is swift, efficient; here and gone. Right now you can observe Mercury at its best. Get out and look. Don’t miss our cosmic messenger.
Penumbra Eclipse, March 24th – 25th
Get ready for a penumbral lunar eclipse on the night of March 24th and 25th, which is visible from any location on Earth where the Full Moon is above the horizon at the time. This area includes the Americas, Antarctica, Alaska, and north-eastern Russia. This month’s Full Moon is called the Worm Moon, and it is the first Full Moon of the spring season. More about the eclipse. In a penumbral eclipse the Moon passes through an outer region of the Earth’s shadow called the penumbra. As the outer part of the Earth’s shadow, the Earth appears to cover part of the Sun’s disk, but not all of it as shown above. Consequently the Moon’s brightness will be reduced since it receives less light to reflect, yet the whole Full Moon’s disk remains illuminated albeit dimmed and darker by a noticeable degree.
The penumbral eclipse begins at 10:53 pm and continues to dim until it reaches its peak at 1:13 am. At that time, the Moon will be 95% within the Earth’s penumbral shadow. The Moon leaves the Earth’s penumbra at 3:32 pm. Okay, I know it’s late to be up to look at an eclipse. I get it. Give it your best effort. I mean, set your alarm at least. If you manage to roll out of bed for a few moments, and through a mental haze look out a window and indeed experience the eclipse, that is true commitment and commendable. I applaud that.
It’s time for stargazing. Sure, you still need to dress warm, wear a hat and gloves, and tolerate the cold, but all a little less so. Transition is in the air. The payoff is to comfortably gaze at these celestial events. Can you do me a favor? After you find and gaze upon comet p12/Pons-Brooks, notice the other colorful jewels tossed haphazardly across the late winter night, and feel just how expansive the universe is. Look around and inhale a March night sky.
Oh, and on the 19th, the spring equinox, if you’re inclined go ahead and try to stand an egg on end. (It’s an old wives’ tale; you can only do it on the equinox.) In truth, you can balance an egg on end any day of the year, if you’re patient. Happy spring.
Clear skies to you!
