Misc: He led the Mormons to the Great Salt Lake.?

Questions

In 1946 Gregory---------- , actor, dancer, born. ?

In 1961 Element 103, ---------- , first produced in Berkeley, California lab. ?

In 1962 Mrs. ---------- gives the TV audience a tour of the White House. ?

In 1972 John and ---------- guest-host The Mike Douglas Show for the entire week. ?

In 1564 Galileo---------- , astronomer, born. ?