Upcoming Events at the Observatories
Follow this page for the latest information on events happening at the Observatories. Please note that times and dates may change. View the Calendar Page for the full year schedule. Check back here for the latest information.
Open House
All Weather Event ~ November 14, 2026 ~ 7:15 PM
All Interested Welcome To Attend!
Last call to observe 9:45 PM
7:15 PM Outdoors: Observatories Open/ Telescope Set-up, Observing through evening weather permitting
7:30 PM Outdoor Presentation / Welcome announcements / Electronic Assisted Astronomy. Bring your binoculars as we guide you with lasers to see celestial highlights. RAS members will use Camera equipped telescope and follow our tour to project images on amphitheater screen.
7:30 PM (only if cloudy skies prevail) Indoor Presentation / “Astronomy gift Ideas for the Holidays ” Jarred Claar
9:45 PM Last call for telescope views
10:00 PM Event ends
Educational Programs by Rittenhouse Astronomical Society
Open House
All Weather Event ~ November 14, 2026 ~ 7:15 PM
All Interested Welcome To Attend!
Last call to observe 9:45 PM
7:15 PM Outdoors: Observatories Open/ Telescope Set-up, Observing through evening weather permitting
7:30 PM Indoor Presentation / Welcome announcements
8:45 PM Outdoor Presentation / “Celestial Highlights” bring your binoculars for a laser guided sky tour.
9:45 PM Last call for telescope views
10:00 PM Event ends
Educational Programs by Rittenhouse Astronomical Society
Open House
All Weather Event ~ October 10, 2026 ~ 7:15 PM
All Interested Welcome To Attend!
Last call to observe 9:45 PM
7:15 PM Outdoors: Observatories Open/ Telescope Set-up, Observing through evening weather permitting
7:30 PM Indoor Presentation / Welcome announcements
8:45 PM Outdoor Presentation / “Celestial Highlights” bring your binoculars for a laser guided sky tour.
9:45 PM Last call for telescope views
10:00 PM Event ends
Educational Programs by Rittenhouse Astronomical Society
Open House
All Weather Event ~ September 12, 2026 ~ 7:15 PM
All Interested Welcome To Attend!
Last call to observe 9:45 PM
7:15 PM Outdoors: Observatories Open/ Telescope Set-up, Observing through evening weather permitting
7:30 PM Indoor Presentation / Welcome announcements
7:30 PM Indoor Presentation / Cosmovision and Observational Astronomy in the Mid 21st Century, Deborah Skapik The Astronomy in Chile Educator Ambassadors Program (ACEAP.)
8:45 PM Outdoor Presentation / “Celestial Highlights” bring your binoculars for a laser guided sky tour conducted by RAS members.
9:45 PM Last call for telescope views
10:00 PM Event ends
Sunset 7:18 PM
Nightfall 8:50 PM
Educational Programs by Rittenhouse Astronomical Society
Observing Opportunity
Observation Opportunity
Saturday August 15, 2026
This event is conducted if clear skies are prevalent at sunset.
Check Rittenhouse Astronomical Society Discord site later in afternoon for evening outlook.
RAS Members, those interested in membership, and Observatory Volunteers are welcome to set up their own personal gear to observe from the amphitheater of the Ryan Observatory. This opportunity provides a secure dark sky location and practice with your equipment.
Sunset 8:02 PM
Nightfall 9:44 PM
Bring your own personal gear to observe.
A Rittenhouse Representative will be on site at Astronomical Twilight to turn of lighting for deep sky observation and photography.
Observing Opportunity
Observation Opportunity
Friday August 14, 2026
This opportunity is provided for Volunteers and RAS members if clear skies prevail at sunset. Check Rittenhouse Astronomical Society Discord site later in afternoon for evening outlook.
Observatory Volunteers, Rittenhouse Members and those interested in membership are welcome to set up their own personal gear to observe from the amphitheater of the Ryan Observatory. This opportunity provides a secure dark sky location and practice with your equipment.
Sunset 8:02 PM
Nightfall 9:44 PM
Bring your own personal gear to observe.
A Rittenhouse Representative will be on site at Astronomical Twilight to turn of lighting for deep sky observation and photography.
Open House
All Weather Event ~ August 8, 2026 ~ 7:15 PM
All Interested Welcome To Attend!
Last call to observe 10:15 PM
7:15 PM Outdoors: Observatories Open/ Telescope Set-up, Observing through evening weather permitting
7:30 PM Indoor Presentation / Welcome announcements
7:40 PM Indoor Presentation / 250th Anniversary Celebration: David Rittehouse, Our Forgotten Pioneer Astronomer , Ted Williams- RAS President Join us as Ted channels David Rittenhouse to our visitors from a unique perspective.
8:45 PM Outdoor Presentation / “Celestial Highlights” bring your binoculars for a laser guided sky tour.
10:45 PM Last call for telescope views
11:00 PM Event ends
Sunset 8:10 PM
Nightfall 9:54 PM
Educational Programs by Rittenhouse Astronomical Society
Observing Opportunity
Observation Opportunity
Friday July 31, 2026
This event is conducted if clear skies are prevalent at sunset.
Check Rittenhouse Astronomical Society Discord site later in afternoon for evening outlook.
RAS Members, those interested in membership, and Observatory Volunteers are welcome to set up their own personal gear to observe from the amphitheater of the Ryan Observatory. This opportunity provides a secure dark sky location and practice with your equipment.
Sunset 8:19 PM
Nightfall 10:07 PM
Bring your own personal gear to observe.
A Rittenhouse Representative will be on site at Astronomical Twilight to turn of lighting for deep sky observation and photography.
Observing Opportunity
Observation Opportunity
Saturday July 25, 2026
This event is conducted if clear skies are prevalent at sunset.
Check Rittenhouse Astronomical Society Discord site later in afternoon for evening outlook.
RAS Members, those interested in membership, and Observatory Volunteers are welcome to set up their own personal gear to observe from the amphitheater of the Ryan Observatory. This opportunity provides a secure dark sky location and practice with your equipment.
Sunset 8:25 PM
Nightfall 10:16 PM
Bring your own personal gear to observe.
A Rittenhouse Representative will be on site at Astronomical Twilight to turn of lighting for deep sky observation and photography.
Observing Opportunity
Observation Opportunity
Friday July 24, 2026
This opportunity is provided for Volunteers and RAS members if clear skies prevail at sunset. Check back here the afternoon before event for final weather call.
RAS Members, those interested in membership and Observatory Volunteers are welcome to set up their own personal gear to observe from the amphitheater of the Ryan Observatory. This opportunity provides a secure dark sky location and practice with your equipment.
Sunset 8:25 PM
Nightfall 10:17 PM
Bring your own personal gear to observe.
A Rittenhouse Representative will be on site at Astronomical Twilight to turn of lighting for deep sky observation and photography.
Observing Opportunity
Observation Opportunity
Friday July 17, 2026
This opportunity is provided for Volunteers and RAS members if clear skies prevail at sunset. Check back here the afternoon before event for final weather call.
Members and Volunteers are welcome to set up their own personal gear to observe from the amphitheater of the Ryan Observatory. This opportunity provides a secure dark sky location and practice with your equipment.
York College is looking for community outreach opportunities and would like to schedule private tours of ROMR. York College will provide bus transportation for up to 20 participants. RAS is seeking three volunteers to operate the domes and speak about observatory processes. The event will take place on Friday evening from 5:00–9:00 PM. Volunteers who sign up are expected to remain available the following day in case the event needs to be rescheduled due to cloud cover or rain.
Sunset 8:31 PM
Nightfall 10:26 PM
Bring your own personal gear to observe.
A Rittenhouse Representative will be on site at Astronomical Twilight to turn of lighting for deep sky observation and photography.
Observing Opportunity
Observation Opportunity
Thursday July 16, 2026
This opportunity is provided for Volunteers and RAS members if clear skies prevail at sunset. Check back here the afternoon before event for final weather call.
Members and Volunteers are welcome to set up their own personal gear to observe from the amphitheater of the Ryan Observatory. This opportunity provides a secure dark sky location and practice with your equipment.
Sunset 8:31 PM
Nightfall 10:27 PM
Bring your own personal gear to observe.
A Rittenhouse Representative will be on site at Astronomical Twilight to turn of lighting for deep sky observation and photography.
Open House
All Weather Event ~ July 11, 2026 ~ 7:15 PM
All Interested Welcome To Attend!
Last call to observe 10:15 PM
7:15 PM Outdoors: Observatories Open/ Telescope Set-up, Observing through evening weather permitting
7:30 PM Indoor Presentation / Welcome announcements
7:40 PM Indoor Presentation / Are Aliens Visiting Earth? A Balanced Perspective, Robert Naeye, Former Editor: Sky and Telescope Magazine
9:00 PM Outdoor Presentation / “Celestial Highlights” bring your binoculars for a laser guided sky tour.
10:15 PM Last call for telescope views
10:30 PM Event ends
Sunset 8:34 PM
Civil Dusk 9:06 PM
Educational Programs by Rittenhouse Astronomical Society
Observing Opportunity
Observation Opportunity
Sunday June 21, 2026 / 8:00 PM
This opportunity is provided for Volunteers and RAS members if clear skies prevail at sunset.
Volunteers, RAS Members and those interested in membership, are welcome to set up their own personal gear to observe from the amphitheater of the Ryan Observatory. This opportunity provides a secure dark sky location and practice with your equipment.
A Rittenhouse representateve will be on site by Nautical Dusk (see below) to turn off lighting to provide darkest skies for astrophotography.
Overnight camping is not permitted at the observatory. It is available in Muddy Run Campground. Please know most campground sites are tree covered.
Sunset 8:37 PM
Civil Dusk- 8:09 / Nautical Dusk- 9:51 / Astronomical Dusk- 10:39PM
Nightfall 10:39 PM
Bring your own personal gear to observe.
A Rittenhouse Representative will be on site at Astronomical Twilight to turn of lighting for deep sky observation and photography.
Open House
All Weather Event ~ June 13, 2026 ~ 7:15 PM
All Interested Welcome To Attend!
Last call to observe 10:15 PM
7:15 PM Outdoors: Observatories Open/ Telescope Set-up, Observing through evening weather permitting
7:30 PM Indoor Presentation / Welcome announcements
7:35 PM Indoor Presentation - Stellepardy, Family Fun: Jeopardy with all Astro categories
8:45 PM Outdoor Presentation / “Celestial Highlights” bring your binoculars for a laser guided sky tour.
9:45 PM Last call for telescope views
10:00 PM Event ends
Educational Programs by Rittenhouse Astronomical Society
Observing Opportunity
Observation Opportunity
Saturday May 16, 2026 Sunset
This opportunity is provided for Volunteers and RAS members if clear skies prevail at sunset.
Heated bathroom access till 10:00 PM / Visitor Center is not open
No overnight Observing, members and volunteers must vacate by Midnight.
Volunteers, RAS Members and those interested in membership, are welcome to set up their own personal gear to observe from the amphitheater of the Ryan Observatory. This opportunity provides a secure dark sky location and practice with your equipment.
A Rittenhouse representateve will be on site by Nautical Dusk (see below) to turn off lighting to provide darkest skies for astrophotography.
Overnight camping is not permitted at the observatory. It is available in Muddy Run Campground. Please know most campground sites are tree covered.
Sunset 8:14 PM
Civil Dusk- 8:45 / Nautical Dusk- 9:23 / Astronomical Dusk- 10:05 PM
Nightfall 10:05 PM
Bring your own personal gear to observe.
A Rittenhouse Representative will be on site at Astronomical Twilight to turn of lighting for deep sky observation and photography.
Open House
All Weather Event ~ May 9, 2026 ~ 7:15 PM
All Interested Welcome To Attend!
7:15 PM Outdoors: Observatories Open/ Telescope Set-up, Observing through evening weather permitting
7:30 PM Indoor Presentation / Welcome announcements, Rock Snake Community Project
7:35 PM Indoor Presentation - Dr. Lydell Nunn Astrophotography
8:45 PM Outdoor Presentation / “Celestial Highlights” bring your binoculars for a laser guided sky tour.
9:45 PM Last call for telescope views
10:00 PM Event ends
Educational Programs by Rittenhouse Astronomical Society
Open House
All Weather Event ~ April 11, 2026
All Interested Welcome To Attend!
7:15 PM -Outdoor Activity: Observatories and telescopes, open for observation (weather permitting)
7:15 PM -Outdoor Activity: Steppin to the Stars- Jump your way across the galaxy
7:30 PM - Indoor Presentation: Welcome
7:35 PM - Indoor Presentation: Ellie the Bunny Hops to the Moon: Amelia Rose DiMaio
7:50 PM - Indoor Presentation: Artemis II - David Walker
8:20 PM - Indoor Presentation: Introducing our new “Arts Laureate” Ophelia Chambliss
8:30 PM - Outdoor Activity: Observatories and telescopes, open for observation (weather permitting)
8:50 PM - Outdoor Presentation: Environmental Augmentation-Soundscapes- Ryan Arbeiter
8:00 PM - Outdoor Presentation: Celestial Highlights, Binocular laser guided tour
9:45 PM -Last call for Telescope Observation
10:00 PM -Event Ends
Arts Night!
Amelia Rose DiMaio will present a short intro to our arts night and speak about her book, Ellie the Bunny Hops to the Moon.
David Walker will speak on We introduce our new Arts Laureate Ophelia Chambliss. Members are always welcome to set up their telescopes and assist the attending public with the view.
Stellar Survey
Virtual Gathering: Stellar Survey
April 1, 7:00-8:00 PM
Wednesday April 1 , 2026 7:00 PM
This gathering is for RAS members, Ryan Observatory Volunteers and Arcadia University
Check our Discord Site or check your e-mail for Zoom meeting codes.
Volunteers, Members and Arcadia University Students are welcome to gather virtually as we Zoom our Stellar Survey program live from the Ryan Observatory. This provides an opportunity to experience virtually how small group observing sessions (under 8 people) are conducted in the observatory. Members and volunteers who are interested in volunteering to operate the observatory are encouraged to attend.
Sunset 5:55 PM
Nightfall 7:24 PM
Bring your own personal gear to observe.
A Rittenhouse Representative will be on site at Astronomical Twilight to turn of lighting for deep sky observation and photography.
Messier Marathon Observing Opportunity
Messier Marathon
will not be conducted tonight due to overcast forecast.
March 21, 2025 cancelled
Bring your own personal gear to observe.
Observing Opportunity
Observation Opportunity
Friday February 27 , 2026 Sunset
This opportunity is provided for Volunteers and RAS members if clear skies prevail at sunset. Check back here the afternoon before event for final weather call.
Enter Before Sunset as main gate Closes at Sunset 5:45 PM
Heated bathroom access till 10:00 PM / Visitor Center is not open
No overnight Observing, members and volunteers must vacate by 11 PM.
If you arrive and gate is not open, line up on right side of entrance driveway.
Gate opens again from 7:00 through 7:10 PM
No Entrance after 7:10 PM
(headlights coming up the hill destroy dark adaptation)
Members, their guests, and Volunteers, are welcome to set up their own personal gear to observe from the amphitheater of the Ryan Observatory. This opportunity provides a secure dark sky location and practice with your equipment. Remember to dress warm as park temperatures can be much cooler than those in neighboring cities of Philadelphia and Lancaster.
Sunset 5:55 PM
Nightfall 7:24 PM
Bring your own personal gear to observe.
A Rittenhouse Representative will be on site at Astronomical Twilight to turn of lighting for deep sky observation and photography.
Observing Opportunity
Solstice Observing Opportunity
December 21, 2025
Enter Before Sunset, Gate Closes at Sunset
Gate opening 6:00-6:10 PM
Gate Opening 7:00-7:10 PM
Heated bathroom access till 10:00 PM
No overnight Observing visitors must vacate by 12:00 PM
Arrive before sunset : Gate Closes at Sunset
If you arrive and gate is not open, line up on right side of entrance driveway.
Gate open 6:00-6:10 PM
Gage opens again 7:00-7:10 PM
No Entrance after 7:10 PM,
(headlights coming up the hill destroy dark adaptation)
Park is closed after sunset (usually 5:00 PM.)
We may have the Discord site operating on a voice & video channel. You might also reach us there.
Members and their guests, Volunteers, Amateurs (from any astronomy group or society, and those interested in membership) are welcome to set up their own personal gear to observe from the amphitheater of the Ryan Observatory. This opportunity provides a secure dark sky location and practice with your equipment. With good conditions, we can see the Milky Way from the Observatory site.
Bring your own personal gear to observe.
A Rittenhouse Representative will be on site at Astronomical Twilight to turn of lighting for deep sky observation and photography.
Open House
All Weather Event ~ December 13, 2025
All Interested Welcome To Attend!
7:15 PM Observatories Open / Telescope Set-up, Observing through evening weather
7:30 PM Indoor Presentations / Welcome announcements
7:35 PM Indoor Presentation - Amelia Rose DiMaio will present a short intro to our arts night and speak about her book, Ellie the Bunny Hops to the Moon.
7:50 PM Indoor Presentations -Ashley Zelinskie will share her work in astronomical art.
8:45 PM Outdoor Presentation / “Celestial Highlights” bring your binoculars for a laser guided sky tour.
9:45 PM Last call for telescope views
10:00 PM Event ends
Educational Programs by Rittenhouse Astronomical Society
Open House
All Weather Event ~ November 8, 2025
All Interested Welcome To Attend!
7:15 PM Observatories Open / Telescope Set-up, Observing through evening weather
7:30 PM Indoor Presentation
8:45 PM Outdoor Presentation
10:00 PM Visitor Center closes , Event Ends
Educational Programs by Rittenhouse Astronomical Society
Open House
All Weather Event ~ October 11, 2025
CANCELED
Out of respect for our volunteer staff, the October 11th Open House at Ryan Observatory is canceled.
We hope you’ll take part in ‘Observe the Moon Night’ from your own backyards and join us in November.
Observing Opportunity
Observation Opportunity
Saturday September 27, 2025
This event is conducted if clear skies are prevalent at sunset.
Check our Discord site later in afternoon for evening outlook.
Members of any astronomical society, volunteers, and those interested in starting a membership are welcome to set up their personal astronomy gear to observe from the Ryan Observatory Amphitheater. Binoculars are considered astronomical observing gear! There is no presentation, just fellow amateurs enjoying the view.
Camping overnight at the observatory is not permitted. Overnight stays can be accommodated at Muddy Run Campground.
A Rittenhouse representative will be on hand at Civil Dusk (time below) to turn off lighting for dark sky and astrophotography observations. Membership with RAS can be renewed or initiated on site with personal check, PayPal, or credit card.
Sunset 6:53 PM
Civil Dusk-7:20 / Nautical Dusk- 7:51 / Astronomical Dusk- 8:23 PM
Nightfall 8:23 PM
Bring your own personal gear to observe.
Observing Opportunity
Observation Opportunity
Saturday September 20, 2025
This event is conducted if clear skies are prevalent at sunset.
Check our Discord site later in afternoon for evening outlook.
Members of any astronomical society, volunteers, and those interested in starting a membership are welcome to set up their personal astronomy gear to observe from the Ryan Observatory Amphitheater. Binoculars are considered astronomical observing gear! There is no presentation, just fellow amateurs enjoying the view.
Camping overnight at the observatory is not permitted. Overnight stays can be accommodated at Muddy Run Campground.
A Rittenhouse representative will be on hand at Civil Dusk (time below) to turn off lighting for dark sky and astrophotography observations.
If interested in joining our society, Membership with RAS can be renewed or initiated on site with personal check, PayPal, or credit card.
Sunset 7:05 PM
Civil Dusk-7:32 / Nautical Dusk- 8:03 / Astronomical Dusk- 8:35 PM
Nightfall 8:35 PM
Bring your own personal gear to observe.
Open House
All Weather Event ~ September 13, 2025
All Interested Welcome To Attend!
7:15 PM Observatories Open / Telescope Set-up, Observing through evening weather permitting
7:30 PM Indoor Presentation Rock Snake Community Project Dawn Brooks
7:40 PM Indoor Presentation Archeoastronomy
8:45 PM Outdoor Presentation Celestial Highlights Ted Williams
9:45 PM Visitor Center closes
10:00 PM Event Ends
Educational Programs by Rittenhouse Astronomical Society
Observing Opportunity
Observation Opportunity
Wednesday September 3, 2025
This event is conducted if clear skies are prevalent at sunset.
Check our Discord site later in afternoon for evening outlook.
Members of any astronomical society, volunteers, and those interested in starting a membership are welcome to set up their personal astronomy gear to observe from the Ryan Observatory Amphitheater. Binoculars are considered astronomical observing gear! There is no presentation, just fellow amateurs enjoying the view.
Camping overnight at the observatory is not permitted. Overnight stays can be accommodated at Muddy Run Campground.
A Rittenhouse representative will be on hand at Civil Dusk (time below) to turn off lighting for dark sky and astrophotography observations.
If interested in joining our society, Membership with RAS can be renewed or initiated on site with personal check, PayPal, or credit card.
Sunset 7:32 PM
Civil Dusk-8:00 / Nautical Dusk- 8:33 / Astronomical Dusk- 9:07
Nightfall 9:07 PM
Bring your own personal gear to observe.
Observing Opportunity
Observation Opportunity
Saturday August 29, 2025
This event is conducted if clear skies are prevalent at sunset.
Check our Discord site later in afternoon for evening outlook.
Members, volunteers, and those interested in starting a membership are welcome to set up their personal astronomy gear to observe from the Ryan Observatory Amphitheater. Binoculars are considered astronomical observing gear! There is no presentation, just fellow amateurs enjoying the view.
Camping overnight at the observatory is not permitted. Overnight stays can be accommodated at Muddy Run Campground.
A Rittenhouse representative will be on hand at Civil Dusk (time below) to turn off lighting for dark sky and astrophotography observations.
If interested in joining our society, Membership with RAS can be renewed or initiated on site with personal check, PayPal, or credit card.
Sunset 7:40 PM
Civil Dusk-8:08 / Nautical Dusk- 8:41 / Astronomical Dusk- 9:16
Nightfall 9:16 PM
Bring your own personal gear to observe.
Observing Opportunity
Observation Opportunity
Saturday August 23, 2025
This event is conducted if clear skies are prevalent at sunset.
Check our Discord site later in afternoon for evening outlook.
Members, volunteers, and those interested in starting a membership are welcome to set up their personal astronomy gear to observe from the Ryan Observatory Amphitheater. Binoculars are considered astronomical observing gear! There is no presentation, just fellow amateurs enjoying the view.
Camping overnight at the observatory is not permitted. Overnight stays can be accommodated at Muddy Run Campground.
A Rittenhouse representative will be on hand at Civil Dusk (time below) to turn off lighting for dark sky and astrophotography observations.
If interested in joining our society, Membership with RAS can be renewed or initiated on site with personal check, PayPal, or credit card.
Sunset 7:49 PM
Civil Dusk-8:18 / Nautical Dusk- 8:51 / Astronomical Dusk- 9:27
Nightfall 9:27 PM
Bring your own personal gear to observe.
Observing Opportunity
Observation Opportunity
Saturday August 16, 2025
This event is conducted if clear skies are prevalent at sunset.
Check our Discord site later in afternoon for evening outlook.
Members, volunteers, and those interested in starting a membership are welcome to set up their personal astronomy gear to observe from the Ryan Observatory Amphitheater. Binoculars are considered astronomical observing gear! There is no presentation, just fellow amateurs enjoying the view.
Camping overnight at the observatory is not permitted. Overnight stays can be accommodated at Muddy Run Campground.
A Rittenhouse representative will be on hand at Civil Dusk (time below) to turn off lighting for dark sky and astrophotography observations.
If interested in joining our society, Membership with RAS can be renewed or initiated on site with personal check, PayPal, or credit card.
Sunset 7:19 PM
Civil Dusk-8:28 / Nautical Dusk- 9:03/ Astronomical Dusk- 9:40
Nightfall 9:40 PM
Bring your own personal gear to observe.