Tag: light pollution

Innsbruck by night time lapse

By Phil Plait | July 8, 2012 7:01 am

Photographer Christoph Malin — part of The World At Night, which is making people aware of the beauty of the night sky — spent eight months in Innsbruck, Austria, taking 35,000 photographs of the sky over the city. What he created with them is a lovely and wonderful time lapse video:

The most interesting part of this to me is that the stars are so crisp and obvious even with the city lights below. The skies there in the Alps must be very clear, or else the light pollution from the city would make the sky glow, washing out the stars (of course, the longer exposures needed to see the stars in these photos also makes the city lights look brighter than they are). It’s nice to see those stars shining in the video, and honestly makes me think a trip to Innsbruck wouldn’t be such a bad idea.

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CATEGORIZED UNDER: Astronomy, Cool stuff, Pretty pictures

Science Getaways: Dark skies

By Phil Plait | June 21, 2012 10:38 am

I got an email recently from BABloggee Mark Sunderland, pointing out this photo to me. It shows the Toronto skyline with the Milky Way and thousands of stars blazing behind it.

I had to chuckle: the picture is obviously fake (and now the caption at Flickr says as much, though it didn’t when I first saw it). There’s no way you could see the Milky Way from a city like Toronto. The city lights flood the air with illumination, lighting up the sky and drowning out faint stars. A long exposure photo of the sky over Toronto would make it worse; the sky would be washed out, with only a handful of stars visible. This is called light pollution, and it’s a serious problem for astronomers. That’s why we build our telescopes far from civilization centers.

To really see the stars, you have to get away from cities, to a place with few lights to to compete with the sky. That’s a big reason my wife and I chose the C Lazy U Ranch for our premier Science Getaways vacation. This is a dude ranch nestled in the Rocky Mountains of Colorado, where the nearest large town is Estes Park, 50 km to the northwest, and even that’s blocked by the mountains. The skies there are dark.

Science Getaways is a company my wife and I started to add science to otherwise non-sciencey vacations. For this first one we have a geologist, biologist, and me at the dude ranch. Every day there will be science talks followed by short and long field trips (to accommodate different physical abilities) where we’ll check out the local nature, and at night there will be stargazing sessions. I’m really exited about that last bit (duh). It’s been a while since I’ve used a ‘scope under really clear, dark skies — I have an 8" Celestron and just seeing Saturn (which we’ll do [NOTE ADDED JULY 21 – actually, by this time Saturn may be to low in the west to see – it’ll be behind the mountains. There might be a location on the ranch where we can get a shot at it, though.]) is cool enough… but unlike that composite Toronto picture, the Milky Way over the mountains will be quite real, and quite spectacular. We’ll be looking at nebulae, clusters, and other objects, too, and there will be plenty visible just to the unaided eye. I’ll have binoculars people can use as well, which to be honest is one of my favorite ways to soak up dark skies. It’s amazing what you can see with a decent pair of binocs.

This Getaway is from September 16 – 20, 2012 — just three months from now. We have about 20 spots left open, so if you’re on the fence about this, now’s the time to decide. The skies are calling.

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GLOBE at Night wants you to look up!

By Phil Plait | March 22, 2011 12:00 pm

[I made an error below, I had originally written that Orion was the target constellation, but it’s in fact Leo and Crux. I have updated this page.]

As I recently wrote, light pollution is a real problem. Wasted light from ground illumination goes into the sky, washing out the stars. But just how bad is it?

GLOBE at Night wants to find out. This is an international citizen-science project, trying to map the sky illumination over the entire populated planet. And they need your help!

It’s actually pretty easy. All you have to do is go outside and find Leo (if you are in the northern hemisphere) or Crux (if you’re in the southern). Then look at the stars and try to figure out the faintest ones you can see. Compare that to a GLOBE at Night star magnitude chart and then report your results.

That last link is actually designed to work with phones, too, so you can do this while on the go.

I like this project a lot. It’s simple, easy to do, and using Leo/Crux is smart: they’re both easily recognizable constellations. And the beauty of this project is that it has two outcomes. One is that it shows people just how bad the skies are getting, which is important. But it also simultaneously gets people to do one of my favorite activities of all time: looking up.

And if you’re a teacher, this is a great learning opportunity for your students, too!

GLOBE at Night is running two campaigns, time periods they want people to go out and do this: from March 22 (today) to April 4 in the northern hemisphere, and from March 24 to April 6 in the southern. So go outside and start observing!

CATEGORIZED UNDER: Astronomy, Cool stuff, Science

The skies at night, are too darn bright

By Phil Plait | March 21, 2011 1:00 pm

Light pollution is a serious topic.

The term refers to wasted light that goes up into the sky instead of illuminating the ground. Almost everyone on the planet has seen it; anywhere near a city the glow from all that light goes into the sky, washing out the stars. Even far from urban areas, the effects are felt.

The obvious problem is for astronomers, who have to fight this added light when observing faint objects. To do this we have to build observatories far, far from cities, or even up in space. That’s expensive, inconvenient, and honestly just a pain in the rump.

But there are other issues as well: people lose sight of the sky, lose their ties with it. That’s bad enough, but there is also concern that, like with chemical or other forms of pollution, wildlife is affected. Mating cycles, hunters and hunted, sleeping cycles: all are affected by our wasted light.

In the journal PLoS ONE, a paper has just been published about the amount of light pollution in the sky. It’s sobering. Clouds over cities are very efficient at reflecting the lights (the picture above was taken at night, to give you an idea of how bad this is), and the researchers found that the sky brightness can increase by a factor of ten times in Berlin on cloudy nights. Of course, astronomers don’t observe when it’s cloudy, but the other effects on wildlife are still there… and this effect ranges far outside the city.

They created this map of lights in Berlin, in fact, with the goal of increasing the resolution enough to see just where all the bright and dark spots are:
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