The Chester County Astronomical Society was formed as a non-profit organization dedicated to the education and enjoyment of astronomy for the general public. The Society holds meetings (with member or guest speakers) and observing sessions once a month. Anyone who is interested in astronomy is welcome to attend meetings and become a member of the Society. In addition to the monthly meetings and observing sessions, the Society also provides a variety of services to the public, including astronomy classes as well as telescopes and expertise for "star parties" for school, scout, and other civic groups.
Tuesday, May 12, 2026 - CCAS Monthly Meeting in Room 112, Merion Science Center, WCU (as well as via Zoom). The meeting starts at 7:30 PM, EDT. Guest Speaker: Kenneth Koeplinger, DVAA Outreach Chair & NASA/JPL Solar System Ambassador. His presentation is titled "Stars & Stripes in the Sky: U.S. Astronomy at 250 Years."
Friday, May 15, 2026 - CCAS Monthly Observing Session, Myrick Conservancy Center, BRC. The observing session starts at sunset (Rain date: May 16, 2026).
Saturday, May 23, 2026 - CCAS Special Observing Session, Rushton Woods Preserve, 911 Delchester Rd, Newtown Square, PA 19073.
Saturday, May 30, 2026 - CCAS Special Solar Observing Session, STEMFest at the American Helicopter Museum & Education Center, 1220 American Blvd, West Chester, PA 19380. CCAS participation at the event is scheduled from 10:00 AM to 3:00 PM EDT.
Venus and Jupiter meet after sunset, the Moon passes in front of Venus, summer begins, and deep-sky treasures rise into view. To start June, look west after sunset to spot Venus and Jupiter shining close together, with Mercury joining the view low in the sky. Around June 9, Venus and Jupiter appear especially close in a planetary conjunction. From June 11 through 15, Mercury joins the scene, creating a mini-parade of planets near the western horizon. On June 17, from some locations, the Moon passes in front of Venus in an event called a lunar occultation. For viewers outside the exact viewing path, the Moon and Venus may still appear close together. [Important safety note: For many viewers, this event happens during the daytime. Never point binoculars, a telescope, or a camera near the Sun unless you are using proper solar-safe equipment.]
June also brings the summer solstice, marking the start of astronomical summer in the Northern Hemisphere. And once the sky gets dark, look for the Summer Triangle and deep-sky objects like the Dumbbell Nebula, Ring Nebula, North America Nebula, and Veil Nebula. Additional information about topics covered in this episode of What's Up, along with still images from the video, and the video transcript, are available at https://science.nasa.gov/skywatching/whats-up/
Scientists: A Giant Unseen Planet Could Be Pulling the Strings
Scientists have discovered a strange tilt in the outer solar system that could point to a hidden planet. Known as Planet Y, this possible Earth-sized world might be shaping the orbits of distant objects beyond Neptune. But is it real, or just a gap in our understanding? to learn more about Planet Y, you can watch our full video on YouTube.Paperlink: https://arxiv.org/pdf/2508.14156
The society schedules monthly observing sessions in the Myrick Conservation Center of the Brandywine Red Clay Alliance. The observing sessions, which are planned around the new moon, are open to the public and announced in the Society's newsletter, Observations. Owning a telescope or binoculars is not required; anyone interested in observing the heavens is welcome to show up. If you do have a telescope and need help using it, our observing sessions are a great place to practice and learn from other society members.
The Chester County Astronomical Society's regular monthly meetings include a presentation from an invited speaker or the demonstration of an astronomical project by one of the Society's members. After the presentation, a brief business session is held to review the status of society activities. Meetings typically last 1-1/2 to 2 hours including an informal conversation over refreshments before the start of each meeting.
The Society meets at 7:30 PM the second Tuesday of each month in the Merion Science Center (former Boucher Building) at West Chester University (corner of South Church Street and Rosedale Avenue, West Chester, Pennsylvania). Click for Directions and Maps.
CCAS has partnered with Chester County Lifelong Learning to offer
a six-week program meeting in the spring of 2026. For more information, including dates of the classes, contact our Education Co-Chairs. Learn more about the location, the topics covered, and how to register on the classes page.
Star Parties & "Nights Out"
The Chester County Astronomical Society offers "nights out" to interested organizations including local schools, scouting groups, and other civic groups for the purpose of learning more about the heavens. For example, scouting groups often hold them to earn badges for their members. If your organization is interested in hosting a "night out", please contact us.
Friday, May 15, 2026 - CCAS Monthly Observing Session, Myrick Conservancy Center, BRC. The observing session starts at sunset (Rain date: May 16, 2026).
Saturday, May 23, 2026 - CCAS Special Observing Session, Rushton Woods Preserve, 911 Delchester Rd, Newtown Square, PA 19073.
Saturday, May 30, 2026 - CCAS Special Solar Observing Session, STEMFest at the American Helicopter Museum & Education Center, 1220 American Blvd, West Chester, PA 19380. CCAS participation at the event is scheduled from 10:00 AM to 3:00 PM EDT.
Star parties are national and regional events similar to "nights out" and open to the public. They are held throughout the year. For a list of upcoming national events in 2026, visit the star parties page.
The West Chester University Department of Geology & Astronomy hosts a planetarium show open to the general public on the 2nd Friday of each month. The WCU Planetarium is located in the Schmucker Science Center on Church St. To locate the planetarium, view the campus map.
The shows start promptly at 7:00 P.M. ET and run approximately one hour in length. Late arrivals will not be permitted to enter the planetarium. Each show includes an overview of what is visible in the current night sky and a special focus on some aspect of astronomy.
Reservations are required because the planetarium has limited seating. For contact information, visit the WCU Public Planetarium Shows webpage.
