Dark Skies
Stargazing in the Greater DC Area
The limiting zenith magnitude around here, as we know, is miserable. That is, the magnitude of the dimmest stars we can see directly over our head (where we’re looking through the least sky, and hence, the least pollution) is around 3 (according to a computer model -- I’d like to calculate that myself sometime, based on observation). That means that, according to Sky & Telescope’s latest star chart, we can’t even see half of the stars that make up the major constellations. Oy.
The International Dark-Sky Association has a service that allows you to locate the closest observing sites with dark skies. (Their main goal is to facilitate making all skies dark.) It takes some clicking around to find yourself, since they don’t yet allow simple lat/long entry.
Take a look at the list of close sites near us. The list on that page allows you to click on each location to see a Census Bureau map of the location. (Our actual location is closest to the link in the table below, but for some reason, that URL only turns up one location, out 66 toward Front Royal. A more complete list seems more useful.)
In any event, looks like we need to travel at least 58 miles from here to see 6th magnitude stars. That sucks.
Computer-modelled Zenithal Limiting Magnitudes
| Oakview, Silver Spring: | 2.9 | closest dark skies |
| 950 Herndon Pkwy: | 4.2 | closest dark skies |
| Darnestown house: | 4.9 | closest dark skies |
| My Mom’s house: | 4.9 | closest dark skies |
| Kosters’ house: | 5.8 | closest dark skies |
| Baitcon: | 6.5 | closest dark skies |