Nantucket Maria Mitchell Association and Nantucket Lights Releases Report on the Nantucket Sky Quality Monitoring Project

February 7, 2025

NANTUCKET, MA—– The Maria Mitchell Association (MMA) and Nantucket Lights are pleased to release the Nantucket Sky Quality Monitoring Project (SQM) report by Dark Sky Consulting, LLC. The joint program, launched in 2022, involves collecting night-sky brightness data from around Nantucket Island from citizen-scientists using handheld Unihedron Sky Quality Meters (SQMs) as measurement devices to study light pollution.

 

Observations were made from June 2022 to November 2024 at eight sites (Nantucket Town; Madaket Beach; Nantucket Elementary School; Nantucket Memorial Airport; Altar Rock; 'Sconset; Wauwinet; and Surfside Beach), a ninth site (Cisco Beach) was added in August 2024, for which only three months of data are available. These efforts establish a baseline for assessing the effectiveness of actions to mitigate light pollution going forward.

 

The distributions separate into two broad populations (high development: Nantucket Town; Nantucket Elementary School; and Nantucket Airport) and low/no development: (Madaket; Sconset; Wauwinet’; Surfside Beach; Cisco Beach; and Altar Rock). The darkest readings among the latter tend to occur in spring and summer. For high-development sites, the width of the distribution increases distinctly in summer and its mean shifts toward brighter values. We interpret this as due to an increased population on the island during the summer season.

 

 

 

The group follows the data collection procedure recommended by DarkSky International. Readings are taken under conditions intended to minimize interference from environmental influences. For example, reading does not commence until the end of astronomical twilight, which occurs about 90 minutes after sunset. Observers are encouraged to report only data taken under conditions of clear skies, which is sometimes not possible due to the vagaries of Nantucket weather. Additionally, they avoid obtaining data when the Moon is above the horizon to limit the contaminating effect of its light. Readings are taken after the conclusion of astronomical twilight during the week between the last-quarter and new Moon phases.

 

Analysis of the night-sky brightness measurements since 2022 show that the data are broadly valid and reproducible, and that outlier values can largely be explained by the influence of environmental conditions. Distributions of measurements across various cuts (location, year) are normal as expected for random sampling of the assumed underlying “populations” of night-sky brightness values. And there is not a great deal of night-sky brightness variation from one year to the next, either on a per-site basis or island-wide. From this, we can broadly conclude that light emissions on Nantucket have, in recent years, increased only at a very slow rate. The Nantucket Dark Sky Monitoring Project continues to be monitored, and data is being collected and analyzed.

 

You can find more detailed information on the Nantucket Island Night Sky Quality Report here:
 
Nantucket-Report-FINAL-250123.pdf


Nantucket-Annex-FINAL-250123.pdf


The Maria Mitchell Association was founded in 1902 to preserve the legacy of Nantucket native astronomer, naturalist, librarian, and educator, Maria Mitchell. After she discovered a comet in 1847, Mitchell’s international fame led to many achievements and awards, including an appointment as the first female professor of astronomy at Vassar College. Maria Mitchell believed in “learning by doing” and today that philosophy is reflected in the MMA’s mission statement, programs, research projects, and other activities. The Maria Mitchell Association operates two observatories, a natural science museum, an aquarium, a research center, and preserves the historic birthplace of Maria Mitchell. A wide variety of science and history-related programming is offered throughout the year for people of all ages


###

For Immediate Release

February 7, 2025

Contact: Joanna Roche

jroche@mariamitchell.org

Recent Posts

Bang, Clang, Hiss!

By Jascin N. Leonardo Finger • October 26, 2026
I grew up, quite literally, with hot water radiators in a Colonial Revival from the 1920s.  There was a huge boiler in the basement that chugged and blew hot belching air. It took up one whole area of the basement and I avoided it. I could hang over on the stairs and stare at its flames at the bottom. It scared me. It not only kept the basement very warm but also very dry. While the house had been built in an area that began to slope at our property, between the furnace and the clever drainage system installed by the builders of the house in the 1920s, our basement was always dry. My mother, the queen of rebates (this is the 1970s and 1980s), had her “rebate and coupon table” right in front of this furnace. I remember it always glowed – and I would not doubt that it still had some asbestos around some of its pipes. Maybe another reason I stayed away – perhaps I was warned away at an early age not just because I could burn myself! One of my fondest memories of this house was the clang and hiss of the heaters in the winter. It made me feel instantly cozy, as if I was wrapped in a nice warm quilt. If I was in bed at night and it was snowing, all the more warmth and cozy feeling. It was comforting and a sound and feel I still associate with snow and winter. The street light and the snow falling, spiraling down in that pinkish gold of the light – and the hoped for snow day to come! Forced air systems just don’t do the same thing. And, they suck all the moisture out of the house to boot! They do keep a house quite warm though – but still not the same – and I miss that humidity as do my plants. I reflect back on the hot water radiators – those old cast iron loopy radiators with the valve and perhaps a radiator box to cover them – as it if they kept me super warm. They didn’t. We kept our house at 63F – a lesson I still follow – and it was a big old Colonial-style house so it could be drafty. One reason we had a Franklin stove in our family room and quilts for nighttime television watching! So many times over the course of a winter, I think of that house where I spent about twenty years of my life, and remember the, “Bang, Clang, Hiss!” of the radiators and the coziness they projected. And while, it wasn’t always warm, it was a lot warmer that the Mitchell House would have been in February! JNLF

Maria Mitchell In Her Own Words

By Jascin N. Leonardo Finger • October 19, 2026
October 1. {1857} No place that I have yet seen in Europe has interested me like Abbotsford; no palace has held such royalty. I sat down in the chair which Sir Walter Scott had occupied, and I almost felt his presence; his power I had known nearly all my life . . . . It was rather a sad visit as all such visits must be . . . I had half a mind to sit down and cry, perhaps because the “wizard” was dead, perhaps because I was a little homesick. This date marked the anniversary of Maria Mitchell’s comet discovery on October 1, 1847. At least one of Scott’s books exists in Maria’s personal library today – and I am sure there were more – handed about among family members, as well as available at the Nantucket Atheneum. This was truly an experience and education for Maria – touring through Europe. It was also the first time she had even been away from home for any length of time. She was entering into her third month away from her family and Nantucket – it must not have been easy. Keep in mind – no easy communication – letters only, do not forget. At least a voice at the other end of a phone line can help a bit when one is homesick. (Yeah, no, I’m not a Facetime/Skype kind of girl. I do “live” in the 19 th century!) JNLF

Keep Calm and Bird On: October 2026

October 1, 2026
“If you don’t look, you don’t see. You have to go and look.” -Edith Andrews
Show More