Transit Watchers Flock to the US Naval Observatory

Jun 5, 2012

The scene today at the US Naval Observatory in Flagstaff as the planet Venus appears to move across the disc of the sun. Among the dozen or so telescopes set up by amateur astronomers to view the event was the Naval Observatory's 19th century vintage Clark telescope (foreground). This same instrument was used to view earlier Venus Transits in 1874 and 1882 when it helped define the actual distance the Earth is from the Sun.