Observatory Park was developed at Turner Farm from the old Nike missile site.  Jeffrey Kretsch told Sky and Telescope how the Analemma Society helped turn a former Cold War misile control site into a thriving observatory park.  Back in the 50's Turner Farm was a dairy farm, but with the Cold War in 1955, the Federal Government took 11.7 acres of the farm to build the Nike Missile Control Center W-83 as one of the first of 13 sites where surface to air missiles were installed.  Originally operated by the U.S. Army, in 1961 the complex with its buildings and radar structures was turned over to the U.S. Army Map Service, which a decade later became the Defense Mapping Agency.  Nike missles were obsolete, but the Turner Farm facility was given a new charter to accurately measure the earth's gravitational field by tracking satellites.  How did Observatory Park come about?  Read more at The Making of Turner Farm Observatory in the Star-Gazers Corner of Sky and Telescope.

The DMA facility closed in 1993 and the land turned eventually turned over to the Fairfax County Park Authority (FCPA) in 1999 increasing adjacent parkland that was purchessed in 1975. (Final purchess of the farmhouse was accomplished in 2010).   In 2000, the Analemma Society was formed and shortly after entered into a cooperative agreement with the FCPA for the development of Observatory Park for science education using astronomy.

The first astronomical resource at Observatory Park at Turner Farm was the Remote Astronomical Telescope Observatory (RATO).  The cinder block tower was built in the 1960s by the United States Government as part of the Nike control site.  When acquired by the Fairfax County Park Authority it was adapted with remote computer control of a large telescope and rotating dome. Just north of the main observatory tower is the radio telescope structure built during the 1960s. Earlier versions of both structures were part of the Nike Missile Control Site and later retrofitted by DMA to suit their mission.

The RATO tower is approximately 26 feet high, capped with a 16 foot diameter electrically driven Ash Dome. The building is separated from the telescope support, providing vibration free observing and has recently undergone rennovation. When operational, the plan is to re-install the Mead 16", f/4.5 reflecting telescope (Model DS-16) onto the central GTO equatorial mount made by Astrophysics, Inc. 

The Roll-Top Observatory was built in 2016 through a Fairfax County Park Authority bond initiative, a Mastenbrook grant, and through a generous donation by the Jean and Ric Edleman family. The Roll-Top was dedicated in October 2016 and as the name implies has a section of the roof that rolls away, leaving four telescopes on piers and several other portable telescopes available for public viewing of the night sky.  Public observing is available every clear Friday night throughout the year.  Adjacent to the observing room is a small classroom used for astronomy instruction.  Fairfax County though its Parktakes program offers a host of astronomical courses at the Roll-Top for a small fee.  These courses are presented througout the year.

Time by Light of the Moon 2021
By the Light of the Moon
Photo by Dr. Jeff Kretsch

The analemmatic (human) sundial at Turner Farm Observatory Park in Great Falls, VA made by Eagle Scout candidate Kenny Dieffenderfer and Troop 1547 marked a unique place in sundialing history this July 23rd. The Analemma Society sponsors free Fright night public viewing of the heavens through telescopes at Turner Farm's Roll-Top Observatory. But just outside the Observatory on the sidewalk is Kenny's analemmatic dial. Could this dial tell correct time by the light of the moon?

On July 23rd this question was put to the test. It was almost exactly a full moon and the sky was clear. As can be seen in the accompanying photo taken by Dr. Jeff Kretsch at approximately 10:10pm EDT, the lunar shadow of a volunteer human gnomon cast a shadow of about 9:10pm standard moon civil time. How did this come about?

The important facts needed to make the analemmatic dial tell the correct "moon time" is knowing both the phase of the moon and the declination of the moon. On that night the moon was very close to being exactly a full moon and the declination of the moon was 25 degrees south of the equator. The maximum that the sun ever gets is 23.45 degrees south of the equator at the winter solstice. That means that (with practical precision) even though it was a late July night, the human gnomon must stand on the dial's zodiac walkway at the Dec-Jan winter solstice mark.  The shadow is in nearly exact agreement with clock time. One might say that the moon and sun were in perfect alignment!

nass news 2022 may  zweibrüken observatory

Hochshule KaiserLautern Observatory.  HSKL Photo

 

When is an astronomical observatory not an observatory? When it's playing the roll of R2-D2. 

According to Atlas Obscura, "A university in Germany [Hochschule KaisersLautern, University of Applied Scieces Kaiserslautern at the Zweibrücken campus] has transformed its hilltop observatory into the charming likeness of RD-D2. The blue and white building looks like an oversized replica of the beloved Star Wars robot. The project that transformed the building into this pop culture homage was led by Dr. Hubert Zitt, an immense fan of the franchise who even gives lectures on the films. He and his students were quickly able to paint the observatory and turn it into the quirky attraction it is today."

"The building itself is a small public observatory that holds a 14-inch reflector with a myriad of filters and attachments. The place, though part of the university, is not used for science and is instead used for public showings."

Atlas Obscura link: https://www.atlasobscura.com/places/zweibrucken-r2-d2-observatory?mc_cid=75548a5d3c&mc_eid=9fa6642923