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There is a point on the drive up Observatory Road in Voorhees State Park when you might reasonably wonder whether your GPS has made a mistake.
The road climbs into the wooded hills of Hunterdon County, away from the more familiar parts of the park. The New Jersey Astronomical Association even addresses the uncertainty on its website, reassuring first-time visitors that, yes, they really should keep driving into the park and continue roughly half a mile uphill.
At the top is something few New Jerseyans would expect to find in the woods: a working astronomical complex built around a telescope weighing, with its massive mount, more than four tons.
This is the Paul Robinson Observatory, home of the New Jersey Astronomical Association, or NJAA, and its 26-inch reflecting telescope. The association describes it as the largest telescope in New Jersey regularly open to the public.
That last part is what makes the place particularly intriguing. The telescope is not simply a historic scientific instrument kept behind a rope. On public observing nights, weather permitting, ordinary visitors can look through it.
And what they are looking through is a remarkable piece of New Jersey scientific history.
Voorhees State Park occupies land that was once part of the farm of Foster McGowan Voorhees, New Jersey’s governor from 1899 to 1902. When Voorhees died in 1927, he left his 323-acre farm, known as Hill Acres, to the state for forestry demonstration purposes.
During the Great Depression, the park became a Civilian Conservation Corps camp. From 1933 until 1941, CCC workers planted trees and constructed trails, shelters and picnic areas. Their work helped shape the park visitors know today.
Then, in the early years of the Space Age, another group arrived with a rather different purpose.
The New Jersey Astronomical Association was founded in 1965 by seven amateur astronomers who wanted to build and use a telescope.
It was an ambitious undertaking for an organization of amateur astronomers, and the location made sense. The observatory sits high in the park, at an elevation the state lists at approximately 840 feet. More than six decades later, NJAA remains there under a lease administered through the New Jersey Department of Environmental Protection.
The result is an unusual layering of New Jersey history. A landscape preserved through the generosity of a former governor and developed in part by a Depression-era federal work program later became home to an organization born just as Americans were becoming fascinated by rockets, satellites and the race to the Moon.
Four tons of astronomy
A 26-inch telescope sounds impressive, but the number does not convey the physical scale of the instrument inside the Paul Robinson Observatory.
The 26 inches refers to the diameter of its primary mirror. A larger mirror gathers more light, making it possible to see objects that would be faint or invisible through smaller instruments.
NJAA says the telescope was originally configured as an f/4 Newtonian reflector and was later converted to a Cassegrain design. The change is more than technical trivia. A Cassegrain arrangement folds the path of incoming light through the telescope, allowing observers to use the instrument without having to climb to an eyepiece positioned high above the floor.
The telescope is supported by an enormous modified German equatorial mount acquired from Indiana University, where, according to NJAA, it had been used for astronomical research. The iron mount alone rises nearly seven feet.
Keeping something that large steady enough for astronomy requires more than a sturdy floor. Its foundation extends about 20 feet into the mountain’s bedrock.
Together, the telescope and mount weigh more than four tons and rise nearly 15 feet above the observatory floor.
For a first-time visitor, those dimensions may be the point when the idea of an “astronomy club” needs some recalibration.
From amateur astronomy to actual research
The distinction between amateur and professional astronomy has always been a little more complicated than the words suggest. Amateur astronomers may not make their living studying the universe, but some operate sophisticated equipment, collect useful observations and contribute data to professional research.
NJAA provides a particularly good example.
The Paul Robinson Observatory has been assigned observatory code W67 by the Minor Planet Center, the international clearinghouse for observations and orbital data involving asteroids, comets and other small bodies. The Minor Planet Center operates under the auspices of the International Astronomical Union.
NJAA has also documented collaboration with Lowell Observatory in Arizona.
More recently, the club’s 26-inch telescope was pointed toward something considerably farther from home.
In July 2025, NJAA member Stephen D. Blazier used the telescope to image 3I/ATLAS, only the third confirmed interstellar object ever observed passing through our solar system. The resulting sequence consisted of 195 30-second exposures and captured the faint object moving against the background stars.
That makes for an extraordinary contrast. On one Saturday night, a child might climb up to the eyepiece for a first look at Saturn. On another night, the same observatory can collect images of an object that arrived here from another star system.
A little bit of Buzz Aldrin in the Jersey woods
The observatory complex also carries the name of one of New Jersey’s most famous explorers.
The Buzz Aldrin Astronomical Center is named for Apollo 11 astronaut Edwin “Buzz” Aldrin, who was born in Glen Ridge and grew up in Montclair before becoming the second human being to walk on the Moon.
The center serves as NJAA’s gathering and educational space, hosting meetings, astronomy lectures, youth programs and special events.
There is something fitting about finding Aldrin’s name here. New Jersey’s connection to the Apollo astronaut is well known, but at Voorhees the connection is placed in a broader continuum. The building is not simply commemorating someone who went to the Moon. It is being used to teach new generations how to understand the sky he traveled through.
That educational mission remains central to the association.
Visiting NJAA
Throughout the year they host a variety of events for space buffs! Here are a few of the opportunities that happen throughout the year. All are free, but donations are appreciated!
1. Astronomy Talks
On every 4th Saturday from March – October, NJAA’s Qualified Observers welcome visitors beginning at 8:30 p.m. During this talk guest speakers provide some history and lead a tour of the facilities. If the weather cooperates, telescopes are opened for observing. This event happens live but is also streamed online..
2. Night Sky Observing
Every Saturday from 8:30pm-10pm from June – October you can tour the observatory and look through the powerful telescopes to observe the night sky.
3. Solar Observing
The association also offers Sunday afternoon solar observing, using telescopes specifically equipped for safe observation of the Sun. Depending on solar conditions, visitors may see sunspots and prominences. This occurs every Sunday between June and October from 2-5pm.
4. Annual Open House & Flea Market
Every year NJAA hosts an open house from 10am-5pm which features the opportunity to explore the observatory and visit vendors selling equipment. The 2026 date is September 19th from 10am-5pm.
Reservations are not required for individual visitors, but groups of 10 or more should contact the association in advance. They also encourage you to bring your own telesope!
Before going: Check NJAA’s website for the current schedule, program changes and sky/weather conditions. Astronomy is one attraction that cannot guarantee the main event.
Walk 3 billion miles before dinner
There is now another astronomy experience at Voorhees that does not depend on clear skies.
A Solar System Trail, created in cooperation with the New Jersey Department of Environmental Protection and funded through the Federal Highway Administration’s Recreational Trails Program, turns a quarter-mile walk into a model of the solar system.
The distances between the interpretive panels are proportional to the planets’ positions in the real solar system. The scale is one to 10 billion, meaning every step along the trail represents roughly 2 million miles in space.
It is a clever way to communicate something astronomy books often struggle to convey: space is mostly space.
Walking from one marker to the next gives visitors a physical sense of the enormous distances involved, and it makes a natural daytime companion to an evening at the observatory.
More than a relic from the Space Age
It would be easy for a place founded in the early 1960s to become a monument to an earlier era of amateur astronomy.
NJAA has not.
Alongside its flagship telescope, the association now operates several smaller specialized observatories. Luna 1 is devoted primarily to deep-sky astrophotography. Luna 2 contains a 14-inch Celestron EdgeHD telescope for visual observing and imaging. Luna 3 supports planetary imaging, spectroscopy and other scientific work.
Members can also train to become Qualified Observers. After six months of membership, they become eligible to enter the program that teaches them to operate the historic 26-inch telescope.
The association runs observing events, educational programs and telescope workshops, while its recent programming has included astrophotography, meteor-shower observing and even radio astronomy demonstrations devoted to detecting hydrogen emissions from the Milky Way.
That combination of old machinery and new technology is one of the most appealing things about the place. The massive telescope mount belongs to an earlier age of astronomical engineering, yet the observatory around it is dealing with digital imaging, spectroscopy, computerized instruments and data that can contribute to contemporary astronomy.
📍 Observatory Road, Glen Gardner
🌐 https://www.njaa.org/
🗓️ Be sure to check website calendar for dates and times of events
