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.
A notable recent find was discovering seasons on the moon, using the European Southern Observatory's Very Large Telescope in Chile. Discovery and flyby. Triton was found on Oct. 10, 1846, just 17 days after Neptune was discovered. According to NASA, Triton was known simply as  the satellite of Neptune  until 1949, when a second moon (Nereid) was found.