How often does a star explode as a supernova?
In a typical galaxy like our Milky Way, a supernova pops off about every 100 years. From our earthly vantagepoint, we cannot see every supernova that occurs in our galaxy because interstellar dust obscures our sight. The Kepler supernova, which occurred 400 years ago, is the last supernova seen inside the disk of our Milky Way. So, statistically, we are overdue for witnessing another stellar blast. Curiously, the Kepler supernova was seen to explode 30 years after Tycho Brahe witnessed a stellar explosion in our galaxy. The nearest recent supernova seen was 1987A, which astronomers spied in 1987 in our galactic neighbor, the Large Magellanic Cloud. Why are supernovas important? All stars make heavy chemical elements like carbon and oxygen through a process called nuclear fusion, where lighter elements are fused together to make heavier elements. Many chemical elements heavier than iron, such as gold and uranium, are produced in the heat and pressure of supernova explosions. These heavy
