About Us


The Seattle Astronomical Society (SAS) is a 501(c)(3) non-profit organization, created and sustained by members who share a common interest in the observational, educational, and social aspects of amateur astronomy. Established in 1948, the SAS includes a diverse collection of people of all ages, occupations, educational levels, and astronomy experience, ranging from beginners to professional astronomers. This diverse membership supports the general objectives of the SAS, which include promoting and providing meaningful astronomical activities for SAS members as well as offering outreach and education for the public.

Member Activities

Monthly Meetings

SAS meetings are normally scheduled on the third Wednesday of each month at 7:30 p.m. in the Physics/Astronomy Building at the University of Washington. The meetings feature programs and lectures on many aspects of astronomy, presented by professional scientists as well as accomplished amateur astronomers.

New Member Meetings

Meetings for new members are held at the home of a volunteer SAS member several times a year for the purpose of introducing new members to the club and to elements of astronomy and observing.

Local Star Parties

Two star parties are scheduled for each month: the public Green Lake/Paramount Park Star Parties on the Saturdays closest to the first quarter moon and the private, SAS member-only Rattlesnake Lake Star Parties on the Saturdays closest to the new moon. Also, many impromptu star parties at Rattlesnake Lake and other nearby locations are organized by members throughout the year whenever weather is favorable for observing.

Regional Star Parties

An annual SAS star party for members and guests is scheduled in August at Brooks Memorial State Park, a dark site in eastern Washington. In addition, many SAS members organize small groups for attendance at the Table Mountain Star Party north of Ellensburg, Washington in July or August and at the Oregon Star Party in August.

Annual Awards Banquet

In January the regular meeting is replaced by a members’ weekend banquet at an area restaurant, which features awards presentations, speakers, camaraderie, and good food.

Online Discussion Group

Through the Clouds is an online subscription mailing list and official SAS discussion group. It is open to the general public as well as to SAS members. Anyone who is interested in astronomy may go to https://groups.google.com/forum/#!forum/Seattle_Astro and join Through the Clouds to learn more about astronomy and about the Seattle Astronomical Society

About Outreach

In addition to the monthly meetings and Green Lake/Paramount Park Star Parties, which are free and open to the public, many activities are scheduled specifically for the purpose of bringing astronomy to the public and to students.

Public School Assistance

SAS members routinely volunteer to travel to local public schools for participation in “science night” events, which include observing, when weather and time permit; exhibits of telescopes, books, and other astronomy materials; and presentation of age-level appropriate, hands-on astronomy activities. Also, many individual SAS members provide assistance to public school teachers requesting help with teaching astronomy.

Special Observing Events

Throughout the year special observing sessions open to the public are organized for special astronomical events such as the 2012 Venus transit, solar or lunar eclipses, meteor showers, etc.

Theodor Jacobsen Observatory Public Sessions

From April through October, observing sessions conducted by SAS members are held on the first and third Wednesdays at the Theodor Jacobsen Observatory on the University of Washington campus.

Special Presentations for Clubs and Other Organizations

SAS provides speakers and programs to clubs, educational groups, and other organizations upon request. Examples include participation in Astronomy Day events at the University of Washington and the Museum of Flight, and exhibits at the Pacific Science Center.