Step 1: List the major UN space law treaties in order.
The Outer Space Treaty came in 1967, the Rescue Agreement in 1968, the Liability Convention in 1972, and the Registration Convention in 1975.
Step 2: Eliminate the unrelated years.
1982 is the year UNCLOS was adopted, 1989 is when the Convention on the Rights of the Child was adopted, and 1966 comes before even the first of these space treaties.
Step 3: Place the Moon Treaty correctly.
The Moon Treaty, the last of the five core UN space treaties, was adopted by the General Assembly in 1979.
\[ \boxed{1979} \]