Arlington County is an urban-suburban county located in the Commonwealth of Virginia, directly across the Potomac River from Washington, D.C. It's part of the Washington metropolitan area and is known for its close proximity to the nation's capital, as well as its mix of urban amenities, residential neighborhoods, and historical sites. In 2020, the county's population was estimated at 238,643.

The Friends of Arlington’s David M. Brown Planetarium is a non-profit organization whose purpose is to support the Arlington planetarium and promote public science education.