National Observatory in Georgetown

Image: U.S. Naval Observatory, Washington, D.C., 1880s. Source: Library of Congress.

On April 23, 1872, the delegation was granted access to the United States Naval Observatory and its 10-foot-long equatorial telescope. Three stories high and overlooking the Potomac River, the telescope allowed the group to observe the movements of celestial objects such as the moon and stars in detail in addition to Mercury and the moons of Jupiter. Only five years later, in 1877, the same observatory would gain international attention for discovering the two moons of Mars. The building still exists today and serves as a National Historic Landmark.

Astronomical observations were limited in Japan until the Meiji era (1868 – 1912), when the government tasked astronomers to calculate the exact time and date using the stars as part of a new national project. Only a few years after the delegation returned to Japan, in 1888, the Tokyo Astronomical Observatory was established at the University of Tokyo, marking the first large-scale observatory in Japan since the Asakusa Observatory in 1782.


Kume, Kunitake. “THE UNITED STATES OF AMERICA.” In Japan Rising: The Iwakura Embassy to the USA and Europe, edited by Chushichi Tsuzuki and R. Jules Young, 67. Cambridge: Cambridge University Press, 2009.

The National Astronomical Observatory of Japan. “History.”