Cherenkov Telescope Array
The Cherenkov Telescope Array or CTA is a multinational, world-wide project to build a new generation ground-based gamma-ray instrument in the energy range extending from some tens of GeV to above 100 TeV. It is proposed as an open observatory and will consist of two arrays of Imaging Atmospheric Cherenkov telescopes, a first array at the Northern Hemisphere with emphasis on the study of extragalactic objects at the lowest possible energies, and a second array at the Southern Hemisphere, which is to cover the full energy range and concentrate on galactic sources. The physics program of CTA goes beyond high energy astrophysics into Cosmology and Fundamental Physics.
CTA intends to improve the flux sensitivity of the current generation of IACTs such as MAGIC, HESS, and VERITAS by an order of magnitude. It will foreseeably consist of tens of IACTs of different mirror sizes. Production of the first telescope prototypes will start in 2013. CTA is designed and will be built by an international collaboration of scientists, with a strong involvement of European institutions. The project is on the road-map of the European Strategy Forum on Research Infrastructures (ESFRI), the European Astroparticle Physics network ASPERA and the European Astrophysics network ASTRONET.
The entire project, with its planned 19-dish array in the Northern Hemisphere and its 99-dish array in the Southern Hemisphere is expected to cost about €200 million (US$ 277 million).
As of March 2015, the CTA Consortium consists of over 1,000 scientists and engineers from 197 research institutes, 5 continents and 29 countries: Argentina, Armenia, Australia, Austria, Brazil, Bulgaria, Canada, Croatia, Czech Republic, Finland, France, Germany, Greece, India, Ireland, Italy, Japan, Mexico, Namibia, Netherlands, Norway, Poland, Slovenia, South Africa, Spain, Sweden, Switzerland, the UK and the USA.
On 10 April 2014 Government representatives met in Munich and decided to start negotiations with the two sites for the planned array in the Southern Hemisphere: Aar in Namibia and ESO's Paranal–Armazones site in the Atacama Desert of northern Chile, keeping Leoncito in Argentina as a third option. Negotiations are expected to conclude in August 2015. 
On 26 March 2015, the CTA Resource Board, composed of representatives of ministries and funding agencies, met in Heidelberg to determine with whom to begin site negotiations for the location of the telescope array in the northern hemisphere. Five candidate sites were considered: two sites in the USA (Arizona), one site in Mexico and two sites on Spain’s Canary Islands. The voting members, representing Argentina, Austria, Brazil, Czech Republic, France, Germany, Italy, Japan, Poland, South Africa, Spain, Switzerland and the UK, decided to begin negotiations with two countries: Spain (La Palma) and Mexico (San Pedro Mártir). Arizona will be kept in consideration as a possible back-up site. After negotiations, the Board will select the final site in November 2015. 
Following the site selection, the project will move forward with construction of the first telescopes on site planned for 2016.
- Official web page of CTA
- Official web page of ESFRI
- Official website of ASPERA
- Official website of ASTRONET
- "Panel homes in on sites for γ-ray detector". Nature - international weekly journal of science. 17 April 2014. Archived from the original on 30 April 2013. Retrieved 30 April 2014.
- "Countries and Institutes in CTA". cta-observatory.org. 30 March 2015. Retrieved 30 March 2015.
- "ESO Site Shortlisted for Cherenkov Telescope Array". ESO - European Southern Observatory. 15 April 2014. Retrieved 29 April 2014.
- "Site Negotiations for CTA North" (PDF). CTA Project Office. 26 March 2015.