Calar Alto TNO Survey
Image: Wikimedia Commons
The Calar Alto TNO Survey is a research programme run from Calar Alto Observatory, high in the Sierra de los Filabres mountains of Almería, southern Spain.
About Calar Alto TNO Survey
Calar Alto Observatory is jointly operated by Spain's CSIC and the German Max Planck Institute, with operations transferred to the Junta de Andalucía in 2019. The site sits at roughly 2,168 metres and hosts several telescopes, including the 3.5-metre instrument that remains the largest on the European mainland, alongside 2.2m, 1.23m and 80cm Schmidt telescopes.
Telescopes & research
The TNO survey uses this instrumentation to search for trans-Neptunian objects — small icy bodies orbiting beyond Neptune — as part of the observatory's broader work on asteroids and cosmological surveys.
Location & getting there
The site is located in the Europe region, in Almería province, Spain, at high altitude in the Sierra de los Filabres, a setting chosen for its dark, stable skies.
Visiting Calar Alto TNO Survey
Calar Alto Observatory publishes visiting information on its official website; checking there before travelling is the best way to plan a trip, since this survey programme itself is a research effort rather than a separate visitor site.
See your named star from here
A facility built to track faint, distant objects by their exact coordinates could just as easily be pointed toward the RA/Dec of a star you've named. Browse our star-naming packages or the star catalogue to name your own.
Opening hours and public-visit programs vary by season. Check Google Maps for current times before you travel.
