Just a few decades ago, Supernova 1987A was temporarily visible to the naked eye. But ancient astronomers also witnessed a number of these "guest stars" pop up in our night sky.
[아하! 우주] Powerful X-rays found on Jupiter solve a 30-year-old mystery archyde.com - get the latest breaking news, showbiz & celebrity photos, sport news & rumours, viral videos and top stories from archyde.com Daily Mail and Mail on Sunday newspapers.