It’s a sad fact that most denizens of the 21st century live under less than optimal skies. Growing up in Northern Maine, I failed to realize just how fortunate I was to have pristine night skies overhead, right from my doorstep.
Today, I live in downtown Norfolk, Va., and like most residents on the United States east coast, I’m lucky to see stars down to magnitude +3. There are darker sites within an hour drive, but work and family life often rules out such a night-long expedition. Dark observing sites are to amateur astronomers what secret fishing holes are to fishermen: coveted and jealously guarded bits of wisdom.
These days, I’m often simply popping up to our apartment’s parking garage rooftop for a quick evening’s hour worth of observing. Though the skies are bright, it’s secluded, and open to the sky. This same sort of view is common traveling, but we always manage to continue to observe.
Here are some strategies I’ve adapted over the years, to continue observing under less than favorable urban skies:
- Go for bright targets: The moon, planets, satellites and double stars are all small, bright targets, and stand up well to light pollution. We once carried out a successful star party for the Necronomicon science fiction convention in front of the hotel in Saint Petersburg, Fla. with two telescope operators aiming at the only available targets for the night: Jupiter and the moon. Likewise, game night at the University of Arizona campus in downtown Tuscon meant bright stadium lights, and we would end up restricted to brighter targets doing public outreach at the Flandrau Observatory. Having a good repertoire of bright double stars really helps expand the list of seasonal observing targets. Some of my faves are Rigel, Castor (actually a sextuple system) Algieba (Gamma Leonis), and Gamma Delphini.
- Solar observing: By definition, observing the sun is not impacted by light pollution. You don’t even need a crisp clear sky; just a sunny view. Safe white light filters are great for sunspots, and a small hydrogen alpha telescope is a great way to observe and show off solar prominences right from the sidewalk. Plus, unlike a majority of unchanging celestial sights, things are nearly always happening on the Sun, and the view can often change hour-to-hour.
- Deep-sky observing: Light pollution filters have come a long way in recent years, as have the sensitivity range of dedicated deep-sky cameras and image stacking techniques. This has put deep-sky imaging in range of suburban and urban astrophotographers in recent years, a huge plus. Bright condensed targets like open clusters are best, versus fainter diffuse nebulae and extended targets like galaxies. Still, I’ve seen amazing astrophotos of extended objects such as the Trifid or Orion Nebula, taken right from an apartment fire-escape ladder in downtown Manhattan!
Finally, it’s always best to make do with the sky that’s available to you, rather than curse the light polluted sky. We’ve successfully observed and carried out an impromptu public star party from the Las Vegas strip—arguably the most light-polluted place on Earth—where Orion’s Belt was barely visible through the garish glare.
Don’t despair: a bright, clear sky is always better than a cloudy one.