Chilean authorities say a prominent Japanese astronomer who helped develop the international ALMA observatory in Chile has been found slain.

Police in Santiago say 57-year-old Koichiro Morita died from a blow to the head struck by a robber who took his wallet and cellphone early Friday.

A suspect described by authorities has having a long criminal record has been ordered by a Chilean judge to be held for three months pending a murder investigation.

ALMA executive Paulina Boca says Morita was instrumental in creating the observatory on a high plateau in northern Chilean. Scientists come from all over the world to gaze deeper into space than any other telescope could do before.