Tuesday is Christmas, and the sky gives us a present: The brilliant planet Jupiter perched amazingly close to the upper edge of the moon. The moon-Jupiter “conjunction” (pairing) is our biggest astronomical sight in the next two weeks but there are a few notable others. I’ll talk about them below.
A very close moon-Jupiter conjuction for Christmas: I wonder how many of you readers saw Jupiter just above the moon last month. The evening was that of Wednesday, Nov. 28. But Tuesday’s Christmas Day recurrence of the same kind of event will feature the two even closer together.
How soon after sunset can you first detect Jupiter with the naked eye or binoculars? By 5 p.m., the planet will be extremely prominent without optical aid and located about two apparent diameters of the moon, left of the center of the moon. But the separation will be shrinking. Between 6 and 7 p.m. the pair will be tightest, with Jupiter shining intensely a little more than one moon-diameter to the upper left of the big, bright moon. The two objects are a little bit farther apart at 8 p.m. That time is notable because the planet will then be almost directly above the moon.
In space, Jupiter will lie almost two-thousand times farther away than the moon Tuesday night — we’ll just begin seeing them along almost the same line of sight. But if you have even a small telescope you can magnify enough to behold the globe of Jupiter and its four Galilean moons.
Two special treats involving Jupiter’s moons will happen for telescopic observers Tuesday night. One is that they will be lined up with a fifth object, a star a bit farther out from Jupiter than the farthest-out Galilean moon. The other treat is seeing, to the opposite side of Jupiter, the two moons Io and Europa passing marvelously close to each other.
Io is the most volcanic world in the solar system, and Europa has an ocean of water and just possibly life underneath its icy surface. The two moons should be closest to each other in the telescope between about 11 p.m. and midnight Tuesday.
Other sights these next two weeks: Full moon occurs Thursday night or, more precisely, at 5:21 a.m. Friday. Then, next week, the moon gets less bright and raises later and later, allowing us darker skies and better views of the stars.
Each moon-free evening, look very near Jupiter for the bright orange star Aldebaran and V-shaped Hyades star cluster, which together form the face of Taurus the Bull. Orion and his belt of three stars in a row will be prominent, and to its lower left will shine the brightest of all stars, Sirius.
There is another conjunction involving the moon and a planet, but it doesn’t happen until Sunday, Jan. 6, before dawn. That morning, Saturn’s bright point of light will be moderately close to the left of the crescent moon — with the bright star Spica upper right of the moon.
Goodbye 2012, hello 2013: The opening months of 2012 featured splendid high pairings of blazing Venus with the moon and Jupiter — and then, in June, the last “transit” of Venus in front of the sun until the 22nd century.
The summer and autumn brought with them an outrageously large number of cloudy nights in New Jersey. But just the past few weeks, the Geminid meteor shower zoomed in clear skies at rates of better than a meteor per minute at peak.
And there are always surprises: In east Vineland on Dec. 18, I saw a bright, intense section of a December rainbow.
In space exploration, the Dawn spacecraft left orbit of the brightest asteroid, Vesta, and headed off toward a 2015 encounter with the biggest asteroid, Ceres. And the big rover Curiosity landed on Mars and began its travels across the Martian landscape.
So can skies in 2013 possibly top those of 2012? Yes, with two potentially spectacular comets. I’ll tell you about them in my next column.
Fred Schaaf is a local author and astronomer. He can be reached at: