Cool. Like a planetarium. It is humbling to think about the reality of impact events. The Tunguska impact in Siberia 1908 was from an asteroid estimated between 60 m (200 ft) to 190 m (620 ft) in diameter. Wiki: "It is estimated that the Tunguska explosion knocked down some 80 million trees over an area of 2,150 square kilometres (830 sq mi), and that the shock wave from the blast would have measured 5.0 on the Richter scale. An explosion of this magnitude would be capable of destroying a large metropolitan area" Even larger impact events have shaped the direction of life. Can we stop/deflect large bodies on short notice?

So cool. As a kid we still didn't know extrasolar planets existed and now we know 1931 (at least). Can someone explain or help me visualize how a typical star system initiates in a molecular cloud? I see the cloud as a "lumpy" 3D mess where the lumps are areas of higher density. Do some lumps just naturally collapse eventually or do other triggering events like a supernova usually precede star formation?