On the December solstice solstice, we celebrate the (unofficial) first day of winter in the Northern Hemisphere and first day of summer in the Southern Hemisphere. Unofficial? Yes. Winter and summer start at the solstices by tradition, not official decree. Yet these solstices bring very real occurrences to our sky, which you can witness for yourself.
Happy solstice, everyone. The December solstice will come tomorrow at 23:03 Universal Time. At this instant, it’ll be at 5:03 p.m. for the Central U.S., or around sunrise for North and south America, sunset for far-eastern Asia, midnight for Africa and Europe, and noontime over the Pacific Ocean. We in the Northern Hemisphere will have our shortest day and longest night of the year. And yet – if you consider the word day in another light – the longest days of the year come each year in December for the entire globe.
The annual Ursid meteor shower always peaks near the time of the December winter solstice, so, in 2014, look for some possible activity over the next several nights. This shower favors the more northerly latitudes in the Northern Hemisphere, but even at far northerly latitudes, it’s generally a low-key production, not nearly as exciting as the Quadrantids in early January.
The Northern Cross isn’t as famous as its counterpart – the Southern Cross – visible from the Southern Hemisphere or the northern tropics. But the Northern Cross also looks like a cross, and it’s pretty easy to spot. It’s a large, noticeable star pattern.
The star Deneb marks the top of the Northern Cross, and the star Albireo marks the bottom. Tonight you can find the Northern Cross shining fairly high in the west at nightfall, as seen from mid-northern latitudes. It sinks downward during the evening hours, and stands proudly over the west-northwest horizon around mid-evening.
The Northern Cross is what’s known as an asterism. In other words, it’s not a constellation but simply a noticeable pattern of stars. It’s part of the constellation Cygnus the Swan.
Late dawn. Early sunset. Short day. Long night. For us in the Northern Hemisphere, the December solstice marks the longest night and shortest day of the year. Meanwhile, on the day of the December solstice, the Southern Hemisphere has its longest day and shortest night. This special day is coming up on Sunday, December 21 at 23:03 UTC (5:03 p.m. CST). A fun fact about the coming solstice is that it occurs within about two-and-a-half hours of a new moon. No matter where you live on Earth’s globe, a solstice is your signal to celebrate. Follow the links inside to learn more about the 2014 December solstice.
The third-brightest star in Orion, Bellatrix, is often overlooked. And yet Bellatrix is such a wonderful star. The name means “Female Warrior,” which some find odd since the original Arabic title translates as “Conqueror.” But – throughout the world – women understand. Bellatrix represents Orion’s left shoulder. Although it appears only as the 22nd brightest star in our heavens, in reality it is a hot, blue giant some 240 light-years away.
In December, 2014, Venus out briefly after sunset; Mars up the early evening; Jupiter shines from mid-to-late-evening to dawn; Saturn in the southeast predawn; Mercury lost in the sun’s glare.
Tonight, we zoom in on a variable star – a star whose brightness changes – near the bright star Vega in the small but distinctive constellation Lyra the Harp.
The 2015 Quadrantid meteor shower is likely to produce the most meteors before dawn January 4, although in the glare of the almost-full moon.
Yes, we’re still talking about the predawn sky. Tomorrow we’ll shift into to evening sky. I can’t resist showing you these crescent moons in the east before dawn, during the part of each month when you’ll find them there. Tomorrow morning – December 17, 2014 – the bright star near the moon is Spica in the constellation Virgo.