This past weekend I got to visit my uncle in Pittsburgh who just so happens to be an amateur astronomer. Naturally, during the course of my visit the topic of stargazing came up and, as is my custom, I invited him to the annual Star Party held not far from where my parents live in Nebraska. And, as always, he expressed his jealousy of our dark, starry nights. To be frank, I rarely considered the skies over Nebraska to be anything special–until I got a glimpse of the night sky in Pittsburgh. It was seriously like the difference between night and day. In Nebraska, one can see millions, if not trillions, of stars on a clear night. In Pittsburgh, it was difficult to make out many of the stars that are easily visible to the naked eye in Nebraska. Why is there so much difference you ask? It is an interesting phenomenon for certain–better known as light pollution.
According to the GLOBE at Night website, light pollution is defined as
“the illumination of the night sky caused by artificial light sources on
the ground (billboards, streetlights, etc.).” The increase of outdoor
light, due to a growing population and urban sprawl, and the resulting
loss of contrast make it harder to detect fainter stars and nebulae.
When in the middle of a city it is often difficult to see anything but
the brightest stars. Unfortunately the increase in light pollution is
doing more than just ruining an amazing view at night, it is also
affecting animals in the wild, such as sea turtle hatchlings that become
disoriented by beachfront lights.
The GLOBE at Night program raises public awareness about this issue
through its annual international citizen science campaign. People around
the world are encouraged to measure levels of night sky brightness
locally and then post their observations to an online world map. Taken
as a whole, participants can see on a local and global level how light
pollution is affecting the night sky. Dark sky areas will be identified
and, with any luck, preserved for future generations thanks to
participants’ observations. This year’s goal is to increase
participation beyond the 17,800 observations contributed last year. For
more detailed instructions on how to contribute and upload your
findings, follow this link.
In addition, the GLOBE site has links for students, teachers, and
parents to help turn this activity into a mini-science lesson. So have
fun with it! See how many constellations you can find! Try to identify
which star you think is closest to Earth and which phase the moon in.
Can you spot any shooting stars? Don’t forget to make a wish (to save
the black skies)!
Becky for My Wonderful World
Photos courtesy of My Shot Your Shot
Light pollution outside Los Angeles on CA State Route 14– Joseph Nguyen
Second photo:
Star gazing at Pinnacles National Monument in California– Peter Hemming