Winter officially begins today in the Northern Hemisphere. That means each day from tomorrow on will get a little bit longer.For those of us who feel as if there's never enough daylight to get all the stuff done that we need to get done leading up to the holidays, here's a ray of hope:
The longest night of the year is a good time to marvel at how we light up the night. This iconic image, called "Earth at Night," was stitched together from data gathered by a swarm of Defense Department satellites. The "cloudless" view maps the locations of permanent lights on the Earth's surface. It serves as a handy guide for where we live and the state of development around the world.
The lights, overlaid on a map for reference, make clear our preference to settle along coastlines and transportation networks. The interstate system in the U.S., for example, appears as a lattice connecting brighter dots. In northern Africa, the Nile River looks like a bright thread through a sea of darkness.
The brightest areas correspond with the most urbanized areas, but not necessarily the most populated. Note the difference, for instance, between Western Europe and China. More than 100 years since the invention of electric light, some regions of the planet remain thinly populated and unlit. Antarctica looks completely dark, as do vast swaths of jungle in Africa and South America.
For more views of Earth from space, check out these past offerings from the Cosmic Log Space Advent Calendar. We've also included links to other online Advent calendars that have been serving up space images daily since the beginning of the month:
- The Cosmic Log Space Advent Calendar so far
- Door 1 for Dec. 1: Shuttle in spotlight
- Door 2 for Dec. 2: 'Alien' lake seen from space
- Door 3 for Dec. 3: Egypt's river of light
- Door 4 for Dec. 4: Tallest building reaches for the sky
- Door 5 for Dec. 5: Russia's dazzling delta
- Door 6 for Dec. 6: Space skipper vs. the world
- Door 7 for Dec. 7: Pearl Harbor from the heavens
- Door 8 for Dec. 8: Listening for E.T.
- Door 9 for Dec. 9: Blast from the past
- Door 10 for Dec. 10: Volcano caught in the act
- Door 11 for Dec. 11: Chronicling climate change
- Door 12 for Dec. 12: Happy St. Lucy's Day
- Door 13 for Dec. 13: Viva Las Vegas
- Door 14 for Dec. 14: Don't wake the volcanoes
- Door 15 for Dec. 15: Stairways to heaven
- Door 16 for Dec. 16: White Christmas in the Midwest
- Door 17 for Dec. 17: Tracks in the sky
- Door 18 for Dec. 18: Amelia Earhart's final resting place?
- Door 19 for Dec. 19: Lunar eclipse as seen from space
- Door 20 for Dec. 20: Our pale blue dot
- The Big Picture at Boston.com: Hubble Advent calendar
- Planetary Society: Solar system Advent calendar
- Zooniverse Advent calendar