Akashi Municipal Planetarium, Astronomical museum and planetarium in Akashi, Japan.

Akashi Municipal Planetarium is a museum on the Japan Standard Time meridian in Akashi, Hyogo Prefecture. Its pale-panelled clock tower, marked "J.S.T.M." and "SEIKO TIME", rises above a grey drum with rows of windows beside a domed hall. Inside, the 2nd-floor planetarium holds a Carl Zeiss Jena Universal23/3 projector under a 20 m dome with 417 seats; the 16th-floor astronomical observation room houses a 40 cm reflecting telescope, while the 13th-14th floors serve as an observation room.

The facility opened on June 10, 1960, and became a center for astronomical education in the Kansai region. Over the decades, the planetarium underwent several upgrades to integrate current technology and scientific findings.

The planetarium sits directly on the Japan Standard Time meridian and serves as a geographic reference for the nation's timekeeping. This location explains why clocks and timepieces are prominently displayed here, and why many school groups visit to learn about time zones and longitude.

Admission for adults costs 700 yen, while students through high school enter without charge, and operating hours run from 9:30 AM to 5:00 PM. Shows inside the dome theater follow a fixed schedule, so checking program times before visiting is helpful.

The 40 cm reflecting telescope is on the 16th floor, the tower's top level, placed high to reduce heat shimmer from the ground; it is shown to the public at a monthly viewing event. The tower clock is the third: the second, installed in 1978, stopped at 5:46 a.m. when the 1995 earthquake struck and was later moved to Kobe Gakuin University.