McDonald Observatory Plans Outdoor 'Parallax Park'

10 January 2005

FORT DAVIS, Texas — How far away are the stars? How do astronomers find planets around other stars? How do space telescopes contribute to our understanding of the universe? McDonald Observatory is planning a large outdoor exhibit that will allow its more than 100,000 annual visitors to explore how the concept of astronomical parallax, and its more sophisticated cousin, astrometry, help to answer these questions.

“Everything we know about distances in the universe rests on our knowledge of the distances to nearby stars. Take a walk through Parallax Park and find out how we extend our reach from near to very far,” said McDonald Observatory astronomer Fritz Benedict. “It’s a lovely contrast that our growing ability to measure the very small, say the thickness of a piece of paper a half-mile away, provides the distances to stars over 1,500 light years away,” he said.

The Parallax Park concept is being presented today in a poster session at the 205th meeting of the American Astronomical Society in San Diego, Calif. (session 8, Informal Astronomy).

The design concept of Parallax Park is the result of more than two years of efforts from a team of astronomers, astronomy education specialists, exhibit fabricators, and architects to design an interactive exhibit that will complement the other offerings of McDonald Observatory’s Visitors Center.

The exhibit planning team is headed by McDonald Observatory astronomers Fritz Benedict and Mary Kay Hemenway. Benedict has spearheaded efforts in astrometry with Hubble Space Telescope and is involved with NASA’s SIM PlanetQuest mission. Hemenway is an expert in astronomy education. The exhibit firms of Blue Sky Design of Toronto, as well as Alchemy of Design and One+Two Design, Inc. of Portland, Oregon, are also involved in the project.

Parallax Park will consist of concentric circles of stone wall (designed to match the Visitors Center architecture) with a representation of the Sun at the center. The innermost stone wall is 60 feet wide. As visitors progress through the exhibit, following a path that mimics the Earth’s orbit about the Sun, they will experience parallax through objects representing stars at various distances and in various directions.

The exhibit includes interactive components suitable for children’s use, as well as text labels and printed guides, in English and Spanish, that detail how the Park is used to explore the uses of astrometry in modern science. In addition to parallax, visitors will learn about standard candles and the astronomical distance scale.

The project will have a related K-12 education component aligned with the National Science Education Standards. Possible topics for student activities include measurement, variable stars, and size/scale. Some activities are site-specific, but most will be available on the Internet for those not traveling to McDonald Observatory. Hemenway notes that McDonald Observatory’s Educator Advisory Board is very enthusiastic about the project, especially its connections to the history of astronomy and geometry.

Funding for the design and planning of Parallax Park was made possible through Hubble Space Telescope Cycle 11 and Cycle 12 Education and Public Outreach Grant Programs, and the NASA/JPL SIM PlanetQuest (JPL contract #1227563).

Funding is not yet available for the construction of Parallax Park at McDonald Observatory. Anyone wishing to build Parallax Park at their site may obtain the design once it is finalized.

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