A wide variety of coins has been issued in connection with The International Year of Astronomy. A pair of geocoins recorded the large observatories of the northern and southern hemisphere in connection with the International Year of Astronomy.
The so-called geocoins - which are accessories of a new kind of technical hobby, geocaching - cover a wide range of topics.
On one of a pair of these geocoins issued in 2009 the Anglo-Australian telescope and observatory is displayed. The Anglo-Australian Telescope is the main instrument of the Anglo-Australian Observatory. On the obverse of the coin the observatory, its name and the Southern Cross constellation is visible. The unique identification number on the bottom is used for monitoring the way of that very coin through the world, according to the rules of geocaching. The reverse shows was well-known icon of the International Year of Astronomy.
When the observatory was commissioned in 1974, it was the third-largest telescope of the world, the largest under the southern sky.
The second geocoin shows northern sky gazing Gemini North telescope. The telescope built in 2000, has a 8.1-meter diameter mirror that positions it among the largest telescopes of the world. The obverse shows the observatory, its name, and above it the Big Dipper, a part of the Big Bear constellation. The unique identification number is at the bottom. The reverse shows the well-known icon of the International Year of Astronomy again.
