Enjoying EarthSky? Subscribe.

125,554 subscribers and counting ...

Ursid meteors active around December solstice

Ursid meteors radiate from very far north on the sky's dome, near the Big and Little Dippers.

Ursid meteors radiate from very far north on the sky’s dome, near the Big and Little Dippers.

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.

Why do most evergreen trees have a pyramid shape?

evergreen trees conifers

Photo credit: Bill Abbott/Flickr

Those who admire the shape of a Christmas tree might like to know that its shape has evolved in response to wind, snow, and light.

Northern Cross stands upright in west on December evenings

The Northern Cross stands upright in the west on December evenings.

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.

Big iceberg in South Atlantic

The Aqua satellite caught this image of the unnamed iceberg on December 3, 2014.  Image via NASA Earth Observatory.

Landsat 8 acquired this image of an unnamed iceberg adrift in the South Atlantic Ocean on December 3, 2014. Image via NASA Earth Observatory.

On December 3, 2014, satellite images revealed a large iceberg – measuring about 165 square kilometers (64 square miles) – east of the southern tip of South America in the South Atlantic Ocean. This iceberg doesn’t meet the criteria for tracking or naming. NASA Earth Observatory said:

Only icebergs that have a side measuring at least 19 kilometers (12 miles) long are named and tracked by the U.S. National Ice Center. That means nearly round or square icebergs—like the one pictured above—can be quite large and still not meet the criteria for naming and tracking.

Comet Finlay is in outburst!

View larger. | Comet Finlay, via Bob King at Universe Today.  Used with permission.

Nightly position of Comet Finlay from December 18 to January 12. Chart via Bob King at Universe Today, and via Chris Marriott’s SkyMap software. Used with permission.

Comet 15P/Finlay has gotten suddenly brighter. It’s brighter than it was expected to be, at its brightest, for this return near the sun. If you have a small telescope or large binoculars, you can now catch Comet Finlay now in the sky after sunset, not far from the place where the sun went down. It will be very near the planet Mars on December 23 and 24, 2014.

Winter solstice as seen from Stonehenge

Winter solstice sunset at Stonehenge in the mid-1980s. Image via Wikimedia Commons.

Many travel each year to Stonehenge in England – perhaps the most famous of the ancient astronomical monuments found around the world – to be present on the day of the northern winter solstice, which is coming up this Sunday. Most who travel to Stonehenge visit the site early in the morning, to watch as the sun rises above the stones.

Watching solstices and equinoxes from space

How sunlight falls on Earth’s surface during the solstices and equinoxes, as seen from geosynchronous orbit.

Everything you need to know: December solstice 2014

Around the time of the winter solstice, watch for late dawns, early sunsets, and the low arc of the sun across the sky each day. Notice your noontime shadow, the longest of the year. Photo via Serge Arsenie on Flickr.

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.

New Zealand sunset

Photo credit: On Location Photography

Photo credit: On Location Photography

A fiery sunset last week at Styx Mill Reserve in Christchurch, New Zealand. Photo by On Location Photography.

Bellatrix, Orion’s third brightest star, means Female Warrior

11Dec01_430

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.