Vincenzo Cerulli and the Collurania Observatory

The Italian astronomer who built his own observatory in Teramo, doubted the Martian canals and found one big asteroid.

Published 2026-10-23

Interamnia’s story begins with a private observatory in central Italy.^[3]

A home-town observatory

Vincenzo Cerulli was born in Teramo in 1859, studied physics in Rome and continued his studies in Berlin.^[3] In 1890 he founded his own observatory at Teramo and named it “Collurania”. Its main instrument was a 40 cm Cooke refractor bought from the son of British astronomer James Wigglesworth; it had stood in Scarborough before being dismantled and shipped to Italy.^[3]

The canals that weren’t

Cerulli observed Mars at a time when many astronomers believed it was covered in long, straight “canals”. He argued that the canals were not real but an optical illusion — the eye joining faint, scattered details into lines. Later observations confirmed he was right.^[3]

One asteroid, chosen well

On October 2, 1910, Cerulli discovered a new minor planet.^[2] It would be the only asteroid he found, and he named it Interamnia after the Latin name of Teramo.^[3] It turned out to be a remarkable find: today it ranks as the fifth-largest asteroid in the main belt.^[2]

Legacy

Cerulli became a member of several Italian academies, including the Lincei Academy in Rome.^[3] His observatory still carries the Collurania name, and his asteroid carries his town’s.

Numbered citations link to the sources list on the Interamnia overview page.