Observatory Public Nights - Visitor Information

Washington-Crossing Park, Titusville, NJ

Phone: 609-737-2575

Come out to AAAP's Simpson Observatory on any clear Friday night from April through the end October to enjoy an evening under the stars. We are open from sunset to 11:00 PM. Travel light-years through the eyepieces of our professional-grade telescopes and see the wonders of the night sky up close and personal. Our expert astronomers will guide you and answer all your astronomy questions.

The observatory is located in Washington Crossing State Park in Titusville, NJ. It is open only when the twilight sky is clear. To verify that the observatory will be open, please call the observatory at 609-737-2575 on Friday evenings or check our Twitter page for the current status.

How to get to the park: Google Map directions

How to find the observatory in the park: Park Map

  1. 1. Enter Washington Crossing State Park at the Philips Farm Day Use Area entrance off Bear Tavern Road. (Do NOT enter the park at the main gate on Washington Crossing - Pennington Rd.)


  2. 2. Drive past the soccer fields to the camper's parking lot and look for a gate on the left as you enter the parking area. If the gate is locked, the observatory is not open. ** Ignore ** the "Authorized Vehicles Only" sign and drive through the gate and down the gravel road past the camp sites on the right.


  3. 3. After passing through the next gate, turn right onto a paved road. The observatory is on the right just around the bend about 50 yards up the road.


  4. 4. Please park at the Nature Center or along the road with your wheels on the pavement.


We have only a few rules for vistors:

  1. 1. No white lights. White light ruins dark-adapted vision required to see faint objects through the telescopes so please turn off all flashlights before entering the observatory grounds. Also, ensure that your phone and tablet screens and camera flash remain off


  2. 2. At all times, children must be accompanied by an adult who ensures that they do not disrupt the enjoyment of other visitors


  3. 3. Please be considerate of the campers when leaving. They may be sleeping.


  4. 4. Enjoy the wonders of the universe.


The observatory houses a 6.25-inch, f/15 vintage Hastings-Byrne achromatic refractor, and a 14-inch, research-grade, Celestron f/11 Schmidt-Cassegrain reflector. Both scopes are mounted on Bisque Paramount MEs, a completely automated control system that allows our operators to accurately point the telescopes at any celestial object includng the moon, planets, binary stars, nebulae, star clusters and galaxies.

In 2015, the club added a 5-inch Explorer apochromatic refractor with a Mallincam video camera to the Celestron scope. The color image from the camera is displayed on a computer monitor in the observatory.

The observatory building is a slide-roof design constructed by our members in 1978. It allows optimal viewing of the sky in any direction. Come early and watch us roll off the roof.

For additional information, email info@princetonastronomy.org