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.
Two other planets, Uranus and Neptune, were discovered after the telescope was invented in the early 1600s. Astronomer William Herschel, who is credited with discovering Uranus in 1781, wanted to call it âGeorgium Sidus,â (Georgeâs Star) for the British ruler at the time, King George III.