Simulations and activities
There are several excellent Java applets and other simulations that help convey the concepts of parallax and the cosmic distance scale. Several of these are listed here:
- Cosmic Distance Scales is an interesting NASA site that helps you visualise the relative scale of the Universe through a series of zoom-out pages. Similar to “Powers of Ten” without the scientific notation (NASA/GSFC). This site also has a page on the Nearest Star (Alpha Centauri system) and good explanation of parallax and its sginificance in the Cosmic distance scale.
- Stellar Parallax is a Java applet that showing how parallax occurs. This is one of a range of useful scientific simulations maintained by Javalab.
- Atlas of the Universe is a useful website that includes a “zoom-able” graphic showing the location of nearest stars It also contains a handy list of stars within 20 l.y.
- Parallax Activity is part of a much larger Teacher’s Guide to the Universe, prepared for the WMAP cosmology mission. This site has several pages on parallax including some activities that can be done in the classroom to demonstrate the principles of parallax.
- Astrometry is an excellent site on the history and future of astrometry from ESA, the European Space Agency. It has a number of interactive pages and discusses missions such as Hipparcos and GAIA in addition to being an excellent primer on astrometry.
- Powers of Ten is an interactive java applet that goes from the very large (extragalactic) down to the very small (quarks) through a sequence of images. An excellent way to visualise the scale of objects in the Universe.
Other parallax and distance scale sites
- Ned Wright’s The ABCs of Distances from UCLA gives clear outline of key methods of determining cosmic distances and places parallax within this framework.
- The IMSA Astrophysics: Distance Ladder site gives a clear explanation of parallax and its place within the cosmic distance ladder. It was written for capable upper-level high school students.
- Seti Tutorial: Measuring Time and Distance provides a concise overview of parallax and a discussion of related concepts and mathematics.
- Cosmic Reference Guide – Distance Measures is part of an excellent NASA educational resource developed to support the Spitzer Space Telescope.
Space missions
- Hipparcos Homepage for the Hipparcos satellite launched in 1989 and the resultant catalogs. This site also contains a wealth of detail on parallax, astrometric science and the results from the mission.
- GAIA Homepage for ESA’s astrometry mission was launched successfully in 2013
- The Space Interferometry Mission was a NASA astrometry mission due for launch in 2009 but cancelled in 2010.
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