MILESTONES IN NUCLEAR HISTORY

JULY 16, 1945--World's first atomic explosion, by U.S., at Alamogordo, N. Mex.

AUG. 6, 1945--Atomic bomb dropped by U.S., on Hiroshima, Japan.

AUG. 9, 1945--Second atomic bomb dropped by U.S., on Nagasaki, Japan.

JULY 1 AND JULY 25, 1946--First test series, Operations Crossroads, at Bikini.

AUG. 29, 1949--First Soviet atomic explosion, ending U.S. monopoly.

NOV. 1, 1952--World's first hydrogen bomb explosion, by U.S., in Operation Ivy near Eniwetok.

AUG. 12, 1953--First Soviet hydrogen bomb explosion.

MARCH 1, 1954--Biggest U.S. explosion on record (15 megatons). Operation Castle, showers radioactive ash beyond safety zone, burns 23 Japanese fishermen.

OCT. 31, 1958--U.S. begins test moratorium. Russia follows three days later.

SEPT. 1, 1961--Russia breaks moratorium, launches two-month, 50-explosion series up to 58 megatons.

SEPT. 15, 1961--U.S. resumes underground testing in Nevada.

MARCH 2, 1962--President Kennedy announces U.S. will resume atmospheric tests in April, unless Russia signs a no-test agreement, permitting inspections.

APRIL 25, 1962--U.S. resumes atmospheric testing.

This file is automatically generated by a robot program, so reader's discretion is required.