One of the most enjoyable parts of Santa's job must be to see the world from on high on Christmas Eve — but thanks to the astronauts on the International Space Station, we can get a similar view on video. Over the past year, the space station's night flights have produced some fantastic pictures of city lights and auroral displays. This video puts together some of the latest clips posted to NASA's Gateway to Astronaut Photography of Earth.

You're actually looking at five time-lapse clips, strung together for a west-to-east journey:

• The first five seconds are from a trip heading up the U.S. East Coast on Dec. 11, with bright city lights strung up all the way from Boston to New York to Philadelphia to Washington. You'll notice a green auroral glow in the upper left corner.

• The northern lights are the main attraction in the clip running from 0:05 to 0:25. This was the view looking north on Dec. 11 as the station was heading from Nova Scotia to northern Italy.

• Our virtual sleigh travels over Africa, Europe and Asia from 0:25 to 0:50, with the camera pointed toward the northeast. Among the sights from Dec. 4 are the Iberian Peninsula and north Africa, England and France, the Baltic Sea, Moscow and central Russia, and atmospheric airglow that gives way to the beginnings of sunrise in the east. Once again, there's a taste of northern lights in the upper left corner.

• The next clip, from 0:50 to 1:13, chronicles an Oct. 21 pass that begins at the coast of France and heads right across Europe. A couple of lightning flashes can be seen over Italy, then the space station makes its way across Turkey and onward to the Arabian Peninsula.

• My favorite part of the trip runs from 1:13 to the end, and takes in a swath of our planet from Central Asia to South Australia. This video was assembled from pictures taken during the space station's night flight on Oct. 29. Here's how the folks at NASA's Johnson Space Center describe the view:

"The video begins just northwest of the Tibetan Plateau, where the greenish glow is from airglow. The line separating the plateau and the city lights to the right of track are the Himalaya Mountains, with cities like New Delhi, Lahore, and Islamabad standing out. Continuing down track, one can spot the brightly lit city of Calcutta just right of track before flying over Burma and Thailand. Thailand's capital city, Bangkok, is the brightest-lit city in the video. The white lights of the city can be seen nearby the green and purple lights on the Gulf of Thailand, which are fishing boats and oil rigs. Once across the Gulf of Thailand, cities like Kuala Lumpur and Singapore stand out right of track before flying over the island of Java (long, thin island downtrack from Singapore). Near the end of the video the ISS flies southeast over Australia and lightning storms, and the Milky Way can be seen rising in the sky."

There's no soundtrack for the video, but feel free to play Christmas music in the background. You could fire up some "Space Age Santa Claus," or take a listen to the first live music broadcast from orbit: "Jingle Bells." Archive.org has the audio recording from 1965's Gemini 7/6 mission. The harmonica and jingling bells come in around 2:10 in the clip.

And now for something completely different: Check out this sleigh ride over Mars:

Looking for more night flyovers? Here's a sampling:

• 'Amazing' view of comet from space
• The best of NASA's night lights
• See the world from space ... in 60 seconds
• Fly over the southern lights in the space station

And if there's anything you've missed from the Cosmic Log Space Advent Calendar, here's your chance to catch up. We'll present our final image from the calendar on Christmas Day:

• The full Cosmic Log Space Advent Calendar
• Dec. 1: An ornament in outer space
• Dec. 2: The masses in Mecca
• Dec. 3: Santa's shrinking domain
• Dec. 4: The monster of Madagascar
• Dec. 5: Antarctica stripped naked
• Dec. 6: Streaking for home
• Dec. 7: Pearl Harbor from above, 1941-2011
• Dec. 8: The rise and fall of the Dead Sea
• Dec. 9: How an eclipse dims Earth
• Dec. 10: Psychedelic storm
• Dec. 11: Beauty of the Inland Sea
• Dec. 12: Drone-spotting stirs up debate
• Dec. 13: Light up your St. Lucy's Day
• Dec. 14: Satellite spots Chinese aircraft carrier
• Dec. 15: Hooray for Hollywood
• Dec. 16: Olympics under construction
• Dec. 17: Mystery in the Gobi Desert
• Dec. 18: Glow over Miami
• Dec. 19: North Korea's dark ages
• Dec. 20: Happy Hanukkah from space
• Dec. 21: Season's tiltings
• Dec. 22: Circle of power
• Dec. 23: North Pole revealed
• Hubble calendar, from The Atlantic's In Focus
• 2011 Zooniverse Advent calendar

(C) 2011 EUMETSAT

This picture of Earth was taken at 06:00 GMT on Dec. 21 by Eumetsat's Meteosat-9, a meteorological satellite that is stationed in geosynchronous orbit above a point close to Africa's west coast. The picture illustrates how Earth's tilt with respect to the sun creates the darkest night of the year for the Northern Hemisphere, and the longest stretch of daylight for the Southern Hemisphere.

Tonight is the longest night of the year for the Northern Hemisphere, due to the winter solstice. The season officially changes from autumn to winter at 12:30 a.m. ET Thursday ... unless you're south of the equator. In that case, spring is turning to summer.

You probably learned in school why the seasons (and the temperatures) change during the course of the year, but in case you need a refresher on how the 23.5-degree tilt of Earth's axis affects the weather, we have the full story for you. This picture, snapped by Eumetsat's Meteosat-9 weather satellite today, shows the situation graphically.

Meteosat-9 is camped out in a geosynchronous orbit that puts it precisely above an equatorial point on the west coast of Africa. Every day at around 6 a.m. local time, it has a great view of the terminator line between day and night, cutting straight across Earth's disk. The slant of that line changes from day to day, due to the changing orientation of Earth's tilted axis with respect to the sun.

On the day of the December solstice, the slant is at its most extreme angle, leaving the north pole in the dark while exposing the south pole to 24 hours of daylight. That's what you're seeing in the photo above. National borders and crosshairs have been added to help you get oriented properly.

This video, put together by NASA's Goddard Space Flight Center, shows you how the slant changes from one September equinox to the next:

If you check out Eumetsat's near-real-time imagery from Meteosat-9 for 1 a.m. ET (06:00 GMT) Thursday, you can see the solstice effect pretty much at its peak. These pictures of the shifting seasons serve as tonight's offering from the Cosmic Log Space Advent Calendar, which has been featuring daily images of Earth from space during the run-up to Christmas. Feel free to click through these previous images in the series, and check back on Thursday for another satellite image that will take the edge off winter.

• The full Cosmic Log Space Advent Calendar
• Dec. 1: An ornament in outer space
• Dec. 2: The masses in Mecca
• Dec. 3: Santa's shrinking domain
• Dec. 4: The monster of Madagascar
• Dec. 5: Antarctica stripped naked
• Dec. 6: Streaking for home
• Dec. 7: Pearl Harbor from above, 1941-2011
• Dec. 8: The rise and fall of the Dead Sea
• Dec. 9: How an eclipse dims Earth
• Dec. 10: Psychedelic storm
• Dec. 11: Beauty of the Inland Sea
• Dec. 12: Drone-spotting stirs up debate
• Dec. 13: Light up your St. Lucy's Day
• Dec. 14: Satellite spots Chinese aircraft carrier
• Dec. 15: Hooray for Hollywood
• Dec. 16: Olympics under construction
• Dec. 17: Mystery in the Gobi Desert
• Dec. 18: Glow over Miami
• Dec. 19: North Korea's dark ages
• Dec. 20: Happy Hanukkah from space
• Hubble calendar, from The Atlantic's In Focus
• 2011 Zooniverse Advent calendar

Alan Boyle is msnbc.com's science editor. Connect with the Cosmic Log community by "liking" the log's Facebook page, following @b0yle on Twitter and adding the Cosmic Log page to your Google+ presence. You can also check out "The Case for Pluto," my book about the controversial dwarf planet and the search for new worlds.

NASA / NOAA

This picture of Earth at night is based on 1994-1995 satellite data from the Defense Meteorological Satellite Program Operational Linescan System, which maps the location of permanent lights on the planet. The borders of North Korea are outlined in white, with Japan off to the right, China to the left and South Korea below.

The death of North Korea's leader, Kim Jong Il, serves as a reminder that the hard-line communist country has long been in the dark — literally. A white border highlights the dark spot known as North Korea in this visualization of our planet's city lights.

This iconic "Earth at Night" picture is based on data gathered by military satellites in 1994-1995, just after Kim inherited power from his late father, Kim Il Sung. The darkness shows how much North Korea has lagged behind its neighbors — South Korea, China, Russia and Japan — in electrification and industrial development. Updates of the data sets show that there's been no change in North Korea's city-light situation between 1992 and 2009. Check out NOAA's "Science on a Sphere" webpage for more about the "Earth at Night" satellite data project.

A different kind of satellite project shows where North Korea has made progress during the dark age of Kim Jong Il: For years, the Institute for Science and International Security has been using satellite imagery to document the state of North Korea's nuclear program. Pictures acquired from orbit over the past couple of years show new construction at the country's Yongbyon nuclear center.

Here's a recent picture of the Yongbyon site from DigitalGlobe, a commercial satellite imaging venture. ISIS says the blue roofs on a gas centrifuge plant and an adjoining building appear to be part of increased construction activity:

DigitalGlobe

This high-resolution satellite image from DigitalGlobe, acquired on Nov. 4, 2010, shows new construction at North Korea's Yongbyon nuclear site. The building with a deep blue roof is thought to be a gas centrifuge plant.

"Whatever the purpose, these activities show that more is going on at Yongbyon than commonly believed," ISIS analyst Paul Brannan wrote in his latest report. The future of North Korea's nuclear program will be a top concern for the United States and its allies as they assess Pyongyang's leadership transition — and satellites will provide the key data for that assessment.

These satellite views of North Korea serve as today's offering from the Cosmic Log Space Advent Calendar, which presents views of Earth from space every day from now until Christmas. Catch up on these previous entries from the calendar:

• The full Cosmic Log Space Advent Calendar
• Dec. 1: An ornament in outer space
• Dec. 2: The masses in Mecca
• Dec. 3: Santa's shrinking domain
• Dec. 4: The monster of Madagascar
• Dec. 5: Antarctica stripped naked
• Dec. 6: Streaking for home
• Dec. 7: Pearl Harbor from above, 1941-2011
• Dec. 8: The rise and fall of the Dead Sea
• Dec. 9: How an eclipse dims Earth
• Dec. 10: Psychedelic storm
• Dec. 11: Beauty of the Inland Sea
• Dec. 12: Drone-spotting stirs up debate
• Dec. 13: Light up your St. Lucy's Day
• Dec. 14: Satellite spots Chinese aircraft carrier
• Dec. 15: Hooray for Hollywood
• Dec. 16: Olympics under construction
• Dec. 17: Mystery in the Gobi Desert
• Dec. 18: Glow over Miami
• Hubble calendar, from The Atlantic's In Focus
• 2011 Zooniverse Advent calendar

Tip o' the Log to Ezra Klein's Wonkblog at The Washington Post and Afrikent.

Correction for 11 p.m. ET: I mistakenly referred to "Science on a Sphere" as being provided by NASA, when it's actually provided by the National Oceanic and Atmospheric Administration. Sorry about that! Must have been because the first time I saw the "Science on a Sphere" display was at NASA's Goddard Space Flight Center.

Connect with the Cosmic Log community by "liking" the log's Facebook page, following @b0yle on Twitter and adding the Cosmic Log page to your Google+ presence. You can also check out "The Case for Pluto," my book about the controversial dwarf planet and the search for new worlds.

NASA

The lights of the Florida Peninsula and the rest of the southeastern U.S. glow in this picture taken from the International Space Station on Nov. 24.

Florida's city lights shine brightly in this night view from the International Space Station — but there's a completely different kind of glow that frames the edge of our planet. It's known as "airglow," the faint greenish radiance high up in Earth's atmosphere.

You might think airglow comes from the reflected glare of city lights, but it's actually a photochemical reaction caused by the sun's ultraviolet radiation.

During the day, that radiation breaks apart molecules of oxygen and other chemicals, exciting them into a higher energy state. During the night, the molecules recombine, radiating the excess energy as light. As a result, the atmosphere glows in a thin region around 60 miles up.

The glow is so faint that it can't be seen when you're looking up into the sky, or when astronauts are looking directly down from space. But when space travelers look toward the edge of Earth's disk at night, they can see the permanent aurora at the horizon. For more about airglow, check out this explanation from the University at Albany's Bob Keesee, or this one from Discovery News' Jason Major.

We've seen some great views of airglow from the space station over the past year: For more examples, check out these archived PhotoBlog items, and keep an eye on NASA's Gateway to Astronaut Photography of Earth as well as astronaut Ron Garan's postings on Google+ for "Fragile Oasis."

The hits just keep on coming from the space station, and you can expect to see much more when the station's crew is back at its full strength of six astronauts.

Three new crew members are due to arrive this week, just in time for Christmas. In this video, space station commander Dan Burbank reflects on the new arrivals, the holidays and our "indescribably beautiful" planet:

The space station crew's sidelong glance at the Florida Keys, the Florida Peninsula and the rest of the southeastern United States was captured from orbit on Nov. 24. It's today's offering from the Cosmic Log Space Advent Calendar, which highlights views of Earth from space every day from now until Christmas. Catch up on these previous gems from the calendar:

• The full Cosmic Log Space Advent Calendar
• Dec. 1: An ornament in outer space
• Dec. 2: The masses in Mecca
• Dec. 3: Santa's shrinking domain
• Dec. 4: The monster of Madagascar
• Dec. 5: Antarctica stripped naked
• Dec. 6: Streaking for home
• Dec. 7: Pearl Harbor from above, 1941-2011
• Dec. 8: The rise and fall of the Dead Sea
• Dec. 9: How an eclipse dims Earth
• Dec. 10: Psychedelic storm
• Dec. 11: Beauty of the Inland Sea
• Dec. 12: Drone-spotting stirs up debate
• Dec. 13: Light up your St. Lucy's Day
• Dec. 14: Satellite spots Chinese aircraft carrier
• Dec. 15: Hooray for Hollywood
• Dec. 16: Olympics under construction
• Dec. 17: Mystery in the Gobi Desert
• Hubble calendar, from The Atlantic's In Focus
• 2011 Zooniverse Advent calendar

DigitalGlobe / AP

This satellite image provided by the the DigitalGlobe Analysis Center shows the Chinese aircraft carrier Shi Lang (Varyag) sailing in the Yellow Sea. The picture was acquired Dec. 8 by DigitalGlobe's QuickBird satellite.

A commercial satellite operator says it has captured a rare image of China's first aircraft carrier as it sailed through the Yellow Sea, after going through an exercise that's the 21st-century equivalent of finding a needle in a haystack.

DigitalGlobe said the aircraft carrier showed up on a cloud-filled picture snapped on Dec. 8 by its polar-orbiting QuickBird satellite from a height of 280 miles (450 kilometers). An analyst spotted the ship while checking the image on Tuesday, said Stephen Wood, the director of the company's analysis center.

"There is something that is always indispensable about having people involved," Wood told me. The ship was identified "using a combination of the satellite imagery plus open-source material on the Internet, and geography," he said, but "at the end of the day, it still comes down to a person."

Experts have been hoping for months to get a glimpse of the aircraft carrier at sea. The former Soviet Union started building the ship, originally known as the Varyag, but never finished it. After the Soviet breakup, the Varyag ended up in the hands of the Ukrainian government. The ship was auctioned off to the Chinese in 1998. Since then, the Varyag, which has reportedly been rechristened the Shi Lang, has been under refurbishment for sea service.

"This is a ship and a story that has had legs for many years," Wood said.

DigitalGlobe

Don't feel bad if you can't spot the aircraft carrier in this wide-field version of the satellite image from QuickBird. It's in the very center of the picture.

DigitalGlobe said this picture was taken during the carrier's second sea trial, approximately 62 miles (100 kilometers) south-southeast of the port of Dalian. Wood said the picture indicates that the ship is "moving at a decent rate of speed, which would be expected in the middle of the ocean." The U.S. military could no doubt glean more information about the Shi Lang's status, from QuickBird's pictures as well as from classified, higher-resolution imagery.

China says the Shi Lang will be used for research and training, and the project is thought to be part of the country's strategy to expand its presence as a naval power. The Chinese military is expected to build more copies of the ship in coming years. In fact, sources told Reuters in July that a second aircraft carrier was under construction.

"China's next moves have to be watched carefully, or there eventually could be a negative impact on maritime safety in Asia," Yoshihiko Yamada, a professor at Japan's Tokai University, told Reuters at the time.

QuickBird's view of the Shi Lang serves as today's offering from the Cosmic Log Space Advent Calendar, which features an image of Earth from space every day from now until Christmas. Here are the past offerings in the series:

• The full Cosmic Log Space Advent Calendar
• Dec. 1: An ornament in outer space
• Dec. 2: The masses in Mecca
• Dec. 3: Santa's shrinking domain
• Dec. 4: The monster of Madagascar
• Dec. 5: Antarctica stripped naked
• Dec. 6: Streaking for home
• Dec. 7: Pearl Harbor from above, 1941-2011
• Dec. 8: The rise and fall of the Dead Sea
• Dec. 9: How an eclipse dims Earth
• Dec. 10: Psychedelic storm
• Dec. 11: Beauty of the Inland Sea
• Dec. 12: Drone-spotting stirs up debate
• Dec. 13: Light up your St. Lucy's Day
• Hubble calendar, from The Atlantic's In Focus
• 2011 Zooniverse Advent calendar

Update for 10:45 p.m. ET: The Associated Press' Dan Elliott got in touch with a Pentagon spokeswoman, Cmdr. Leslie Hull-Ryde, who said the progress made by the Chinese on the aircraft carrier was in line with the U.S. military's expectations. A Defense Department report to Congress said the carrier could become operationally available to China's navy by the end of next year, but without aircraft. "From that point, it will take several additional years before the carrier has an operationally viable air group," Hull-Ryde told Elliott in an email.