The Gemini Observatory
is an astronomical
observatory consisting of two telescopes
at different sites. The Northern Operations Center is located in
Hilo, Hawaii, and the
Southern Operations Center is in La Serena, Chile. The Gemini telescopes were built and are
operated by a consortium consisting of the United States, United
Kingdom, Canada, Chile, Brazil, Argentina, and Australia.
This partnership is managed by the Association of Universities for
Research in Astronomy (AURA). The United Kingdom had dropped out of
the partnership in late 2007, only to be re-instated again two and
a half months later.
Gemini North at sunset.
At the moment it is open and equalizing its temperature with
the outside air.
One telescope (Gemini North
, also called the
Frederick C. Gillett telescope) is located on
Hawaii's Mauna Kea Observatory.
Its location makes for excellent viewing
conditions due to the superb atmospheric conditions on top of the
over high dormant volcano. It saw first
in 1999 and began scientific operations in 2000.
(Gemini South) is located at over elevation on a
mountain in the Chilean Andes called Cerro Pachón. Very dry air and negligible cloud cover make
this another prime telescope location (shared by several other
observatories, including the SOAR Telescope and Cerro
Tololo Inter-American Observatory).
Gemini South saw first light in
Observatory's international headquarters is located in Hilo, Hawaii at the University of Hawaii at Hilo University Park.
The Gemini South
base-facility is located on the Cerro Tololo Inter-American
Observatory (CTIO) campus in La Serena Chile.
Together, the twin Gemini telescopes provide almost complete
coverage of both the northern and southern skies (Gemini North
presently cannot point north of declination +79 degrees; Gemini
South cannot point south of declination -89 degrees). They are
currently among the largest and most advanced optical/infrared
telescopes available to astronomers. Both
employ a range of advanced technologies to deliver the highest
quality images, including laser guide
, adaptive optics
. In addition,
the two telescopes allow very high-quality infrared observations
due to the advanced protected silver coating of their mirrors and
advanced ventilation systems. Thanks to a high degree of networking
, the Gemini telescopes can be
operated remotely, and observations can be run when atmospheric
conditions suit them best, reducing unnecessary travel by
It is estimated that the two telescopes cost approximately $
184 million to construct, and a night
on each Gemini telescope is worth about $40,000.
The history of the Gemini Observatory featured prominently in
, a 2004 book by science historian
W. Patrick McCray 
. It details the technical and political
challenges faced by scientists and engineers working to construct
Gemini and other modern observatories.
In November 2007 it was announced that the UK's STFC
that, to save £4 million annually, it would aim to leave the
telescope's operating consortium.
At a consortium in January 2008, the conclusion was made that the
UK would officially withdraw from the Gemini Partnership and the
Gemini Observatory Agreement effective December 12, 2007.
As the reason for the UK breaking its part of the agreement seemed
to be entirely financial, there had been public outcry, including
the "Save Astronomy" movement 
which is asking citizens to speak up against the astronomy budget
The UK rethought their decision to withdraw from Gemini, and
requested reinstatement into the agreement, and as of February 27,
2008, were officially welcomed back. They will seek to sell some of
their telescope time to bring in the much-needed funds to continue
their commitment to the agreement.
The two 8 meter mirror blanks, each weighing over , were fabricated
Expansion glass. Each blank was constructed by the fusing together
of and subsequent sagging of a series of smaller hexagonal pieces.
This work was performed at Corning's Canton Plant facility located
in upstate New York. The blanks were then transported via ship to
REOSC, located south of Paris for final
grinding and polishing.