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.
We can't see a lot of features in Neptune's atmosphere, but the features that astronomers can detect appear to come and go in a hurry. When the Voyager 2 spacecraft flew past Neptune in August 1989, for example, it discovered the Great Dark Spot -- a dark, oval-shaped storm system as big as Earth.