Kenwood: Star Parties and Walking to Pluto at Ferguson Observatory

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Kenwood in eastern Sonoma County may be the only wine country town on the planet that can claim a full-scale observatory within its limits - the perfect destination for anyone, child or adult, who is curious about the universe. 

One of the western USA's largest observatories completely dedicated to public viewing and education, Robert Ferguson Observatory is located within Sugarloaf Ridge State Park. Surrounded by a protective ring of hills that decrease light pollution from surrounding cities, Ferguson provides the perfect place to observe the stars and - given the range of telescopic power found here - a good deal more.

The observatory's equipment includes: 

  • A 40' reflecting telescope designed and built by a team of observatory volunteers. This is the largest publicly-accessible optical telescope in California. Mounted on the side is an 8-inch reflecting spotting scope that also functions for observing. The 40-inch telescope rests on an alt-azimuth mounting with a computer drive integrated with planetarium software so the operator can choose a target and command the telescope to that point in the sky.
  • A two-meter-long refractor telescope with a spotting scope and a Telrad finder attached to its side.
  • A 14-inch Celestron Schmidt-Cassegrain Robotic CCD telescope, which allows astrophotography and research; it can image objects hundreds of millions of light years away. Tracking mount, camera, focuser, and filters are all computer-controlled.
  • Solar telescopes that allow observation of the sun, either via direct observation through a heavy filter, or using radio antennae that record fluctuations in the sun's activities. 
  • A radio telescope that feeds radio and audio signals to the indoor classroom computers, making it possible to hear the Sun's activity and to see radio graphs projected on an indoor screen.

Be sure to stroll along the PlanetWalk, a walkable scale model of the solar system. Unlike most other such models, which display either relative planet sizes or the relative distances between planets, PlanetWalk does both. The 'solar system' has been shrunk more than 2,360,000,000 times, small enough to include the orbit of distant Pluto (officially reclassified as a 'dwarf planet'), and large enough that the smallest planets can still be seen. 

PlanetWalk begins at a sign representing the sun and takes you on a 4.5-mile, information-packed, round-trip journey. Each step you take represents nearly one million miles of empty space. As you step through the light years you'll pass trail signs representing each planet in our solar system, drawn to scale and placed at a distance from the sun that's proportional to reality. You'll thus be able to see just how small the planets are compared to the sun's immensity, and how vast the spaces are between planets. 

Events at the Observatory include daytime solar observation, star parties, and much more. Some programs are free, and others typically cost $3 a person. You'll also be charged $8 for parking, so why not come early and enjoy the park's 25 miles of hiking trails? 

Robert Ferguson Observatory 707-833-6979, inside Sugarloaf Ridge State Park 2605 Adobe Canyon Road, Kenwood, 707-833-5712. Find more information at