This Earth Hour, Don’t Forget to Look Up

In 2 days, 23 hours, and 33 minutes [5:12] hundreds of cities around the world will switch off the lights at precisely 8:30 p.m. local time in honor of Earth Hour.

This WWF campaign started in 2007 in Sydney as a kind of public statement on climate change:

“By voting with their light switches, Earth Hour participants send a powerful, visual message demanding action on climate change,” WWF says on the Earth Hour Web site.

Since then, Earth Hour has become a global movement, with more than 4,000 cities in 87 countries going dark for 60 minutes last year. (See pictures of Earth Hours past.)

Clearly the main thrust of Earth Hour is to remind folks that we use a heck of a lot of energy to brighten offices, illuminate landmarks, and advertise Broadway hits—and all that energy consumption equals quite a few greenhouse gas emissions.

But there’s another form of pollution of which Earth Hour participants can easily be made aware: light pollution.


The bright lights of Brisbane, Australia, before Earth Hour 2008 …

About this time last year organizers of the International Year of Astronomy kicked off a citizen science campaign called The Globe at Night, which asked people around the world to let folks know how many stars they could see in a given patch of sky from various locations.

The idea was to shine a spotlight on the fact that urbanites (myself included) don’t get much exposure to the wonders on the night sky, because our vision is tainted by the constant glow of city lights.

Sure, it’s possible to escape the glare by taking a drive out of town. But Earth Hour presents a unique opportunity: For 60 minutes on March 27, you can stand in downtown L.A. and look up at the night sky and actually see stuff!

… and during Earth Hour 2008! Can you see the stars?

Both pictures by Marty Pouwelse, courtesy WWF


The moon should be gorgeous on the night of March 27, as it will be its closest to Earth for the whole month around midnight that night.

But in addition to the usually visible moon, sky-watchers can look for the bright star Regulus shining above the moon, Saturn near the moon’s lower left, the star Spica below Saturn, and another star Arcturus down and to the left.

Regulus is the brightest star in the constellation Leo, the Lion, probably because it’s actually four stars grouped together.

With a small telescope, you should be able to see Regulus as two stellar pairs. You should also be able to spy Saturn’s largest moon Titan.


Titan seems to bounce off Saturn’s rings as seen by the Cassini orbiter.

—Image courtesy NASA/JPL/Space Science Institute

Spica is a big blue-colored star in the constellation Virgo, while Arcturus is an orange giant thought to be about one and a half times the mass of the sun.

And those are just the highlights: A good dark sky should come alive with the billions of stars, nebulae, and other bodies that shine in the void.

If orbital objects are more your speed, you can use this site [before Earth Hour, of course] to find which spacecraft, such as the International Space Station, will be visible in the sky above your city.

So, if you’re in an Earth Hour zone and were wondering what to do for an hour in darkness, grab a sweater and a star chart, and enjoy!

Human Journey