SUNSET: 
6Welcome back, Venus! Brightest planet in the sky returns just in time for the holidays.
"There are so many stars shining in the sky, so many beautiful things winking at you, but when Venus comes out, all the others are waned ...
Mehmet Murat ildan from the play Galileo Galilei (2001)
Project Nightflight
I miss Venus. The brightest planet in the sky leaves a gaping hole in twilight's tableau when she's gone. Missing in action since late September, it feels like an eternity since we last saw her cheery light at dawn. Or dusk.
That's changing … finally! Venus has been inching into the evening sky ever since superior conjunction on October 25th. What's been taking it so long? The planet's on the opposite side of the Sun from Earth and 155 million miles (249.5 million km) away, near its maximum distance.
The farther away something is, the slower its apparent motion, so Venus tediously claws its way up out of the Sun's fierce glare. The opposite situation occurs at inferior conjunction, when Venus swings between the Sun and Earth and tracks rapidly across the sky.
Have faith. Sightings and photos of Venus's return are already trickling in despite its puny altitude at dusk.
Source: Stellarium
From mid-northern latitudes, the planet hovers just 3-6° high in the southwestern sky 20 minutes after sunset in mid-December. Granted that's low, but from an open skyline and equipped with a pair of binoculars, you can be one of the first to welcome back the Solar System's brightest planet the next clear night.
The situation improves throughout the month. By year's end, Venus will stand 8-10° high and be easily visible without optical aid. My method for finding the planet when it's scraping the bottom of the sky is to note the position of sunset (the brightest spot along the western horizon) and make horizontal sweeps with binoculars to the left and right above that point. Soon enough, Venus pops into view.
Wikipedia with additions by the author
From the diagram you can see that as Venus's orbital motion brings it closer to Earth, the planet grows in apparent size and climbs away from the Sun. Its angle to Earth and Sun changes, too, making the planet change phase like the Moon, from full to crescent. This month, Venus is a tiny gibbous lump about 97% illuminated and 10″ across. Through a telescope at 50x, it resembles a minute full moon.
Come spring and early summer, Venus will be out high and bright every evening. Those unfamiliar with the sky will start asking you what that bright thing is in the west after sunset. UFO reports will increase. Venus is like climate change — in the background until it suddenly hits you between the eyes.
Source: Stellarium
In addition to watching the planet ascend to its proper position of radiance, catching one of its many jewel-like pairings with the Moon or a bright planet makes for one of skywatching's greatest pleasures. The coming year offers several must-see events starting on December 22nd when an exceptionally young lunar crescent dangles some 6° north of the planet 20 minutes after sunset.
Source: Stellarium
Between February and August 2015, Venus will pair up with every planet except Saturn. Its conjunction with Jupiter on the evenings of June 30th and July 1st will be the most memorable, when the two luminous heavyweights will be separated by just half a degree.
I think of all the beauty Venus brings to the night sky and am reminded of the wisdom of the ancient Greeks and Romans. They rightly named the bright planet the goddess of beauty and love.
Plan your year with the stars and and planets with the 2015 Sky & Telescope Observing Wall Calendar!
Comments
Joe Stieber
December 10, 2014 at 12:35 pm
An additional problem with sighting Venus after the recent superior conjunction is the shallow angle of the ecliptic after sunset this time of year (so Venus is moving more sideways than vertical with respect to the horizon as it retreats from the sun). My first post-sunset sighting for this elongation was this past Sunday evening, December 7, 2014. We finally had some clear weather, so I went to the local baseball field and picked it up with 10x42 binoculars at 4:40 pm EST (5 minutes after sunset here in southern New Jersey) when it was at 5 degrees altitude. Once I found Venus in the binoculars, I could see it naked eye. I initially spotted Venus after conjunction with 16x70 binoculars mid-afternoon on November 7th when it was just 3.5 degrees from the sun by blocking the sun with my house.
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Bob KingPost Author
December 16, 2014 at 2:00 am
Hi Joe,
Still waiting here in n. Minnesota for a clear evening sky to spot Venus. Chomping at the bit!
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Tony
December 11, 2014 at 6:46 pm
For several months around the time of superior conjunction, the elongation of Venus changes by about 1 degree every 4 days. When the ecliptic angle is steep (or as steep as can be near latitude 50), Venus can stand out very well when only 12 degrees from the Sun. Once it gets within 12, though, even a small change has a big effect on its visibility. Seen from southern Vancouver Island, Venus faded rather rapidly after the second week of September 2014.
During December, the evening ecliptic angle steepens at its most rapid rate in northern mid to high latitudes, so Venus can be expected to "pop" into view by Christmas or New Year's Eve. Over much of 2015 it will be a treat to see Venus shining high in evening then morning skies for the first time since 2012.
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Glenn
December 12, 2014 at 7:26 pm
Venus has an orbital velocity of 35km/s and Earth does 30km/s. At superior conjunction the planets are moving in opposite directions so the relative velocity ( as calculated by a vector subtraction ) is just 5km/s. Hence the tedious Venusian reappearance taking 6 or 7 weeks to become reasonably easily visible as recent pix show. Here in Sydney with a steep ecliptic angle Venus still only sets 55min after the sun. A superior planet such as Jupiter going at 7km/s will reappear much faster as the relative velocity is 23km/s. Of course Jupiter moves into the morning sky since it is slower than Earth while Venus overtakes the sun to become the Evening Star.
At inferior conjunction speedy Venus has a relative velocity of 65km/s to Earth, whipping past us , retrograding and zooming up to greatest elongation in less than 2.5 months. But it's a slow 7.5 months in this apparition until greatest eastern elongation on June 7th
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December 13, 2014 at 12:46 am
I saw it on the 29th of November, from a lofty perch: the summit of Mauna Kea. It was clear and transparent but the inversion was strong enough Venus didn't appear initially as a dot - it was smeared into almost a con-trail-like streak (or a sun-grazing comet). A few minutes later it looked normal, just before it set.
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Glenn
December 15, 2014 at 3:35 am
Edited version incorporating a correction or two. Venus has an orbital velocity of 35km/s and Earth does 30km/s. At superior conjunction the planets are moving in opposite directions so the relative velocity of Venus to the sun ( as calculated by a vector subtraction ) is just 5km/s. Hence the tedious Venusian reappearance taking 6 or 7 weeks to become reasonably easily visible as recent pix show. Here in Sydney with a steep ecliptic angle Venus still only sets 55min after the sun. A superior planet such as Jupiter going at 7km/s will reappear much faster as the relative velocity to the sun is -23km/s. This means Jupiter moves into the morning sky since it is slower than Earth while Venus overtakes the sun to become the Evening Star.
At inferior conjunction speedy Venus has a relative velocity of 65km/s to Sol, whipping past us , retrograding and zooming up to greatest elongation in less than 2.5 months. But it’s a slow 7.5 months in this apparition until greatest eastern elongation on June 6th at 18 hr UT.
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