I just got back from leading a tour in Chile, exploring the amazing southern skies. We annually go into the Andes and Atacama Desert, and went to the mountaintop where they’re building the world’s largest telescope. Its mirror is the size of a house.
I use a special handheld instrument to measure the sky’s purity. Down there, the Milky Way casts shadows. It seems as though you can touch the stars, they’re so brilliant, with the background sky nearly black.
In such pristine conditions, it’s easy to see why the ancient Mayas regarded the Milky Way as the center of all existence. It’s more than a creamy glow; in pure skies, it contains countless intricate inky dust lanes and stunning detail. Okay, so how do our skies compare?
If this were Manhattan, we wouldn’t be having this conversation. But in the Catskills – and also just east of us, near parts of the Taconic Parkway – many people do enjoy excellent skies. Nowadays, sky quality is charted by satellite and the light pollution map plotted using a series of colors. If you go to https://darksitefinder.com/maps/world.html and zoom in, you can discover the sky quality around your own home.
Brooklyn is coded white, meaning that only a few stars poke through the intense sky-glow. Poughkeepsie is coded red; dozens of stars are visible from there, though not the Milky Way. If you live in or can drive to a green area, that’s quite good. That actually comprises much of our region. One patch of the Catskills and a big one in the Adirondacks are even coded dark blue, which indicates an extraordinary sky.
Since these next two weeks are the final period when the Cygnus Milky Way can be seen until summer of 2016, check it out. The Moon is absent the first three hours after nightfall starting this Monday, November 30. After this weekend, we have increasingly moonless nights until the middle of December. Moreover, there’s no snow yet, which makes a difference. Because it’s so reflective, snow cover causes the sky to glow more brightly, since streetlights are reflected upward.
If it’s clear this coming week or next weekend, it might be worth taking a drive to see the cosmos at is best. Next weekend (December 4 to 6) the Moon is totally gone, and Orion and the brilliant winter patterns stand in full display by 9:30 p.m. One area that is almost perfectly pure is reached by going up Route 28 just past Margaretville, then turning left onto Route 30 for about ten minutes. When you reach a bridge crossing the Pepacton Reservoir, both ends have pull-offs for cars. Those spots have truly pure skies.
You don’t need a telescope. You’ll be swept away just gazing up and seeing what the universe really looks like.
Want to know more? To read Bob’s previous “Night Sky” columns, visit our Almanac Weekly website at HudsonValleyAlmanacWeekly.com.