The immediate cause of sudden cardiac arrest is usually an abnormality in your heart rhythm (arrhythmia), the result of a problem with your heart's electrical system.
Version for printing. The first planet to be discovered was Uranus by William and Caroline Herschel on 13 March 1781. It was discovered by the fact that it showed a disk when viewed through even a fairly low powered telescope. The only other planets which have been discovered are Neptune and Pluto.
Pluto was discovered by astronomer Clyde Tombaugh in 1930. A 9th planet had been looked for for some time. It was believed that such a planet had to exist in order to explain some odd things happening in the orbits of Uranus and Neptune.Tombaugh did a careful sky survey at the Lowell Observatory in Arizona.luto was discovered by astronomer Clyde Tombaugh in 1930. A 9th planet had been looked for for some time. It was believed that such a planet had to exist in order to explain some odd things happening in the orbits of Uranus and Neptune. Tombaugh did a careful sky survey at the Lowell Observatory in Arizona.