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Dark Sky Trip Guide

Compiled by Elijah McGill and STAHR Board ’22–’23 for the benefit of all STAHRgazers to come

Useful contacts

Elijah McGill, STAHR Dark Sky Trip TSAR

elijahmcgill@college.harvard.edu

Any of the STAHR board members through our STAHR Slack!

Choosing a Location

Dark Skies

Finding dark night skies is likely going to be your first criterion when choosing a location for a trip. Living in Cambridge, we are unfortunately surrounded by intense light pollution, making it difficult to see all but the brightest stars and planets. Therefore, for a dark sky trip you have to find a place that has less light pollution, which will allow you to see more objects in the night sky. There are plenty of free online maps, such as https://www.lightpollutionmap.info, that allow you to see where light pollution is lower, and click on a location for more technical details on light pollution. The simplest metric is called the Bortle scale, which qualifies light pollution by classes 1-9. Harvard straddles classes 8 and 9, so just about anything is better. However, to make a trip worth it we would recommend trying to get to at least Class 4 skies. Light pollution can be confusing to figure out, so we have a few FAQs below, and feel free to reach out to any STAHR Board Member for help with light pollution and finding dark skies!

Light Pollution FAQs

  • What is light pollution?
    • All the light from streetlights, buildings, cars, and other sources in an urban area is reflected up into the sky. Although any one source of light isn’t that bright, taken together all this diffuse light being thrown up into the sky drowns out relatively faint objects in the sky. As more and more light pollution fills the sky, we lose the ability to see more and more faint stars and celestial objects, until we can see only the brightest.
  • What is the Bortle scale?
    • The Bortle scale is a way of rating the amount of light pollution in a location. It divides the amount of light pollution into nine classes, with 1 being perfectly dark skies. The Bortle class doesn’t just tell you how much light pollution there is: it also tells you what you can expect to be able to see with that amount of light pollution. We generally tend to consider locations using the Bortle Scale, since it provides a useful broad and interpretable metric that can help predict what will be visible at a location! For more information on the Bortle scale see here: https://en.wikipedia.org/wiki/Bortle_scale
  • How dark do I need to get to see the Milky Way?
    • It depends on what kind of experience you’re looking for! Our galaxy becomes visible in skies darker than Bortle 4 

Other Considerations

There are several other criteria worth considering when planning a dark sky trip. First is access to the site. Many parks will close after dusk, and may discourage nighttime access, but might be okay with you visiting later at night if you phone ahead. Another important thing to consider is sightlines. Dark skies will be relatively useless if there are trees or buildings blocking all but the view directly overhead. Areas with wide open fields, bodies of water, or points of higher elevation are all good ideas! Weather is also a huge factor. If there are tons of clouds blocking the sky, you won’t be able to see much! The National Weather Service https://www.weather.gov/ is our preferred forecaster, which is generally the most accurate. Weather forecasts will always get more accurate the closer to the actual time, so keep checking up until it’s time for your trip.

It’s not location-specific, but the phase of the moon can have a HUGE impact on the quality of your dark sky experience. The moon can throw just as much light into the sky as a city. Regardless of where you go, you won’t see much with a full moon in the sky. A new moon is ideal; a waxing crescent will set soon after nightfall, giving you plenty of time to stargaze afterwards; a waning half-moon or crescent won’t rise until after you’ve started driving back home or turned in for the night. Check in advance!

Our Favorite Spots

This is a list of spots STAHR has led Dark Sky Trips to before, or that board members have personal experience visiting and are all good options! The list is in order of closest-furthest to Harvard (which also happens to match worst-best skies). All are doable as one night trips, getting back late the same night you left, except for Baxter State Park which is far enough that it needs to be a trip with an overnight stay.

Halibut Point State Park, Rockport MA

  • Drive Time: ~1 hour + depending on traffic
  • Bortle Class 4
  • Access: free, the park technically closes at sunset, but we’ve been told by park authorities that we’re allowed to stargaze from the parking lot at the entrance after dark.
  • The closest and easiest place that we’ve found with decently dark skies! The Milky Way will likely be faintly visible, and most major constellations will be findable. 

Marconi Beach, Cape Cod National Seashore

  • Drive Time: ~2 hours depending on traffic
  • Bortle Class 3
  • Access: free during the off season (most of both semesters), Cape Cod National Seashore remains officially open until midnight, and if you call ahead will likely say that you’re allowed to stay later.
  • The place where our last few dark sky trips have gone! Although Bortle class 3 vs 4 may not seem like a huge difference, the skies are significantly darker here than at Halibut Point. In fact, these are the darkest skies within a 2-3 hour drive of Boston that are easily reachable in one night. The Milky Way will be obvious, and naked eye objects like the Pleiades and the Andromeda Galaxy will be noticeably more visible than at Halibut Point. Other beaches on the Cape are good but this is the darkest one that is part of the National Seashore, located between towns. The beach provides wide open sightlines which is great, and if you call ahead and show up by 4pm, you can get a campfire permit and have a fire to help stay warm! https://www.nps.gov/caco/planyourvisit/permitsandreservations.htm

Baxter State Park/North Maine Woods

  • Drive Time: ~6 hours
  • Bortle Class 1
  • Access: Baxter State Park itself closes gates overnight. You must have a camping reservation to be in the park overnight. Adjacent Katahdin Woods and Waters National Monument has 24 hour access. Neither are accessible over the winter. However, some surrounding public roads and logging roads tend to be open year round, and if you can find a good viewpoint on those roads it will be nearly as good! 
  • This site is by far the most logistically complicated, but totally worth it! These are the only true perfectly dark skies anywhere east of the Mississippi river, with zero light pollution. The Milky Way will have spectacular definition and detail, and it may be hard to find constellations because of the number of stars visible. It would require an overnight stay and potentially a two day car rental making it noticeably more expensive. If anyone wants to try this one, feel free to reach out to Elijah McGill, our Dark Sky Trip Tsar and a Northern Maine local!

Transportation

Unfortunately, all the destinations mentioned above are only reachable by car. There is a commuter rail line to Rockport, but from the station to the park would require an Uber, by which point it likely remains cheaper to rent a car. For those under 21, generally the only car rental option will be ride sharing apps like ZipCar. For those 21 and up, you can reserve from actual name brand rental agencies, like Enterprise, Hertz, Budget, etc… (though you will be charged a young driver fee until 25). It’s worth looking at these agencies, since they often can end up being cheaper than ZipCar, especially once you factor in mileage to a further away destination. Hertz has a AAA discount, which means if you’re a AAA member it will waive the young driver fee and give you a 20% discount (cars can be as cheap as $50/day after these discounts!!!). If anyone else has any rental discount tricks and tips please let us know!

Stargazing (what to look for)

A Tour Through Time and Space

The moon is always beautiful, especially when it’s setting! Even with just your naked eye, you should be able to see darker spots on the lunar surface – those are the maria, ancient volcanic floodplains the size of entire countries here on Earth.

Moving beyond the moon’s orbit, there are four other planets in our Solar System easily visible to the naked eye: Venus, Mars, Jupiter, and Saturn. They’re often some of the brightest objects in the sky, and are usually easily findable with a phone app!

Here’s a list of some other objects worth finding in the sky!

  • Cassiopeia, Cygnus, the Big and Little Dippers, Draco, Orion: a set of prominent, generally easy to find constellations at our latitude! The Dippers, Cassiopeia, and Draco are almost always visible, while Cygnus and Orion dip below the horizon at different times of the year. Cygnus and Cassiopeia are also useful as waypoints to find the Milky Way, which runs straight through Cygnus and near Cassiopeia. Again, use any of apps recommended below to check what might be visible when you’re going
  • The Pleiades (also known as the Seven Sisters, or the Subaru logo!): a cluster of hot, young stars that looks like a mini Little Dipper. How many of the stars in the Pleiades are visible is actually a good test of how dark the sky is!
  • The Milky Way: it will only be visible in truly dark skies (Bortle 4 at the very least) but is absolutely spectacular in the right conditions! The summer Milky Way is stronger and more visible than the winter Milky Way but both are worth seeing.
  • Andromeda Galaxy and Orion Nebula: two non-star phenomena that can be visible to the naked eye in dark enough skies. The Orion Nebula is a vague blur in the constellation Orion, while the Andromeda Galaxy is near Cassiopeia.

Shooting stars are one of the highlights of any dark sky trip, and you’ll usually see one or two if you keep your eyes on the sky! If you want to see more, you can head to darker skies or run your dark sky trip during a meteor shower. Shower intensity is highly variable between showers and from year to year, but is generally quantified by the zenithal hourly rate (ZHR) — a rough guess of how many meteors you might see in ideal conditions. Generally, showers with a high ZHR peaking on or near a new moon will be the most impressive. Here’s a list of our favorites:

  • Quadrantids: start off the year, peaking shortly after New Year’s. The peak is very short – you may see some of them on other dates, but they’ll be most impressive on the night that they peak. Good news: this shower occurs during our winter break!
  • Eta Aquarids: thrown off by Halley’s comet, these peak just before dawn in early May, but they aren’t much to write home about.
  • Perseids: a classic. They peak in mid-August and are best seen a few hours before dawn. John Denver was inspired to write “Rocky Mountain High” after seeing the Perseids on a dark night in the Rockies!
  • Southern/Northern Taurids: these two showers peak around midnight in early to mid November. While they aren’t very active, they do produce more than their fair share of fireballs, particularly bright meteors blazing their way across the heavens.
  • Leonids: every 33 years, this becomes the most spectacular meteor shower of the year, with potentially hundreds of meteors visible an hour during the midnight peak in mid-November. Unfortunately, the big outburst isn’t expected until the ’30s.
  • Geminids: one of the most active meteor showers of the year, peaking in mid December and becoming clearly visible after about 10pm. Definitely worth watching!

Since the 1950s, our species has put a bunch of satellites in orbit and some of these are visible to the naked eye! If you see an unblinking bright dot moving steadily through the sky, you may have spotted one. If you’re invested in seeing the ISS, check out Spot The Station!

Recommended apps and websites

While we’re not going to be with you to point out objects in the sky, there are plenty of ways to find them yourself. Technology has become pretty amazing in this regard! One thing: if you’re going to be using your phone to find options, you should turn on redshift (explainer here for iPhones). Otherwise your phone screen will ruin your night vision and keep you from seeing the things you’re looking for!

Here are some apps we recommend:

  • Star Walk 2 is a phone planetarium for three dollars. It has lots of detailed information about when stars and planets will rise and set, and has an artificial reality mode that will tell you what objects are in the direction that your phone is pointing towards. It also has a time function, allowing you to see what the sky will look like in fifteen minutes, an hour, or next month. (These are common features of any good stargazing app – Star Walk 2 just has nicely polished versions.)
  • Night Sky is another great phone app. It’s slightly less intuitive than Star Walk 2, but it’s free (albeit with a few features locked behind a very expensive premium option) and has an augmented reality function. It’s also useful for identifying satellites, be they a Starlink or the ISS. Its biggest con is that it has so many objects that it can be a little overwhelming and you can lose your overall view.
  • Sky Map is a nice simple free phone app. It still will show you all the major constellations, stars, and planets, but less of the satellites and other smaller details. It’s particularly great for general situational awareness of the whole sky, since it allows you to zoom out all the way out and see the bigger picture. Getting oriented like that is super helpful!
  • Stellarium is the best thing to use before you go stargazing. It’s a free and easy-to-use computer app that has a TON of data about everything in the sky — most STAHR dark sky trips are planned based on what Stellarium has to say!

Equipment

It is entirely possible to do your own dark sky trip without any equipment and just appreciate what you can see with the naked eye. However, if you do you want to bring any optical aids, we have some suggestions. To begin with, we highly recommend starting with a pair of binoculars instead of a telescope. They’re easier to aim at an object, and help you get a feel for what some magnification might offer at a cheaper intro price. A decent intro pair can be had for around $30 dollars (example here). Anything from 7x to 10x magnification is reasonable and will allow you to see more detail in certain celestial objects.

If you are set on a big telescope purchase, make sure to do your research! Many an astronomy hobby has been killed by people enthusiastically purchasing a telescope that isn’t right for them. There are plenty of hobby groups online – you can look into joining the email list for a local astronomy group (maybe even in your hometown), as people there are always happy to help out a newcomer. There are also plenty of online communities, particularly on Reddit; check out r/telescopes, r/astrophotography, or r/astronomy (most of them have links to wikis in their descriptions with plenty of fun tips). This thread is a particularly good introduction to choosing a telescope. You’re also of course welcome to ask any STAHR board members for advice and their opinions on good intro equipment!

Final Thoughts

Overall, we really want people to get more chances to look at the night sky than what we can offer through our official Dark Sky Trips! We hope this guide helps enable you to see the night sky on your time and dime, and to really appreciate our universe. We will continue offering as many free Dark Sky Trips to the community as our funding allows, since we know self organizing trips is not within everyone’s comfort zone or financial reach. As always, we’re happy to help anybody with any questions, thoughts, or concerns!

Ad astra,

STAHR Board 2022