Heart murmur. Heart murmurs are heart sounds produced when blood flows across one of the heart valves that are loud enough to be heard with a stethoscope. There are two types of murmurs. A functional murmur or physiologic murmur is a heart murmur that is primarily due to physiologic conditions outside the heart. Other types of murmurs are due to structural defects in the heart itself.
Voyager 2 passed Neptune in the summer of 1989, the first spacecraft to observe that planet. Passing about 3,000 miles above Neptune's north pole, Voyager 2 made its closest approach to any planet since it left Earth 12 years earlier.
The first successful flyby of Venus was performed by NASAâs Mariner 2 spacecraft on 14 December 1962, following failed attempts by both the Soviet Union and the USA. The first successful landing was the Soviet Venera 4 lander, which touched down on the surface on 18 October 1967.