Cherry Springs Dark Sky Park

Dark Sky Places Traveling Fellowship Part 3

Thanks to the Winston Churchill Memorial Trust, I have received a traveling fellowship to visit all of the International Dark Sky Places in North America between 22 August and 03 October 2011. This series of blog posts will detail my visit to each of these  very dark places.

Cherry Springs Dark Sky Park

Cherry Springs State Park sits in rural Pennsylvania, in the middle of the 1000 square kilometre Susquehannock State Forest, 700m above sea level, and as such is very dark indeed. Much of the park was built by members of the Civilian Conservation Corps during the great depression of the 1930s, and over the years it has gained fame amongst Pennsylvania residents as one of their most popular parks.

The astronomy field at Cherry Springs State Park

My visit was arranged by Chip Harrison, the park operations manager, who first stumbled upon the idea of a dark sky park back in 1997. While patrolling the park late one night he chanced upon an astronomer, Gary Honis, who had set his scope up in what is now the astronomy field. Rather than ask him to leave (parks close at sunset) Chip asked him why he’d come to that specific site, and Gary told him that, using a light pollution map of the eastern US, this spot was the very darkest place he could find.

Light Pollution Map showing Cherry Springs

Inspired by this, Chip worked with astronomers to protect those dark skies, and in 2000 Pennsylvania named it a dark sky park, the designation became more formal in 2007 when it was declared as the world’s second International Dark Sky Park by the IDA.

The astronomy field now sports electric hook-up sites, rentable telescope domes, landscaping and tree planting to block headlights, and attracts thousands of astronomers each year, most of them during two major star parties: the Black Forest Star Party, sponsored by the Central Pennsylvania Observers of State College since 1999; and the Cherry Springs Star Party, sponsored by the Astronomical Society of Harrisburg since 2005.

Cherry Springs State Park patch

I arrived at the park just days after the Black Forest Star party closed, but there were some astronomers still on the field, and it was a delight to meet them, including Gary Honis, whom Chip had first met 14 years ago.

The local community seems to relish their unique status, with restaurants and hotels displaying “astronomers welcome” signs, but perhaps the most impressive work has been done by the Cherry Springs Dark Sky Fund, headed up by Chip’s wife Maxine. They work on fundraising through private donations and to date have received tens of thousands of dollars worth of money, much from visiting amateur astronomers, which has allowed them to develop the astronomy field, as well as a public stargazing field across the road where weekly stargazing sessions are held on Friday and Saturday nights.

These astronomy nights are hosted by park ranger Greg, who’s enthusiasm is evident. Just recently they had 500+ people turn up for one of these evenings, far more than they could cope with, but which demonstrates the need for such a programme.

The night I spent stargazing there was a little hazy, and the SQM read 21.4, but I have been assured that they regularly get readings as dark as 21.9, with a naked-eye limiting magnitude of 7.2.

All-sky fisheye image taken from Cherry Springs State Park