On the morning of Wednesday, Jan. 9, I looked out a back window of my house as pink dawn was coming on and saw a truly lovely crescent moon hanging low among the trees.
As it turned out, the next morning I woke but fell back to sleep and missed an even better sight: A close meeting of the moon and Venus. Fortunately, however, I had mentioned the event in this column and Janie Halliday went out on the Ocean City beach and took several photos of the pair, which her mother-in-law, Ruth, emailed to me.
What’s more, I have some good news for all of us: Tonight there is another planet pairing with the moon and, even though the planet — Jupiter — is not as bright as Venus, it is still bright and visible high in the sky for much of the night. In addition, tonight’s pairing is much tighter than the moon-Venus one was. And it is just the beginning of two weeks of a very watchable journey of the moon through the sky.
Near and far journey of the moon: Knowing some facts makes the moon’s month-long journey around us even more fascinating.
For instance, did you know that the moon’s distance from Earth varies considerably during the month? Tonight the moon is at its farthest for the month — 251,800 miles. And it was closest for the month almost exactly at the time Halliday was seeing it and photographing it beside Venus, only 223,700 miles from Earth.
Even the morning before Halliday’s observation, when I saw the moon it appeared distinctly bigger than usual. One does have to be careful about these size estimates, though, because there is a famous illusion which often makes the rising or setting moon look larger.
Tonight’s moon-Venus pairing: If tonight is not overcast, we’re in for hours of fascination as the moon slowly drifts past the planet Jupiter.
Find the moon part of the way up the southeast sky at nightfall. By 5:30 p.m., or sooner, as the sky darkens, watch for Jupiter’s point of light to come into view about four apparent widths of the moon to the lower left of the moon’s center.
By 7 p.m., the gap between the two is noticeably smaller and Jupiter is almost directly left of the moon. The greatest drama occurs between 9 p.m. and 1 a.m., during which Jupiter is less than two apparent widths of the moon from the moon’s edge.
You’ll also notice a bright, orange star to the left of both the moon and Jupiter: Aldebaran, the eye of Taurus the Bull. Binoculars can show you that Aldebaran forms a “V” shape with fainter stars that belong to the Hyades star cluster. Not too far to the right of the moon and Jupiter is the tiny dipper-shape of the lovely Pleiades, or Seven Sisters star cluster.
But most of your interest will be focused on the moon-Jupiter pair. Between 9 and 10 p.m., the moon will pass directly below Jupiter. The two are closest together of all between 10 p.m. and midnight, when the moon is to the lower left of the planet.
During that period, your little finger held out at arm’s length should appear wide enough to cover both moon and Jupiter.
The journey continues: After nightfall this Friday, a bright moon lies almost exactly halfway between the bright star Pollux and the even brighter star Procyon. Procyon is the only brilliant luminary in Canis Minor the Little Dog.
Pollux is the brightest star in Gemini the Twins but not far above its only slightly less bright twin, Castor.
By Saturday evening, the moon has moved onward and forms a huge right triangle with Pollux and Procyon. That night, at 11:38 p.m., the moon is exactly full.
Next Monday, the moon rises a few hours after sunset with Regulus, the heart star of Leo the Lion, to its upper left. And, finally, before dawn on Sunday, Feb. 3, an almost precisely half-lit moon shines with Saturn to its upper right.
Fred Schaaf is a local author and astronomer. He can be reached at: firstname.lastname@example.org