 放大圖片
1610年7月的一個晚上，伽利略正就東方的一顆亮星展開新的觀測，令伽利略感到意外的是，他竟然通過望遠鏡看到星的兩旁各有一顆大伴星（圖）。為了在深入觀測期間保有最先發現權，他向外界公布了一個字謎：smaismrmilmepoetaleumibunenugttauiras，宣示他有一項暫不公開的發現（字謎的謎底是「我看到了最遠行星的3重身份」）。1612年伽利略又發現這顆行星的伴星不見了，直到1616年，伽利略終於看到了圍繞著這顆行星的環。沒錯，伽利略觀測的行星正是擁有最漂亮行星美譽的土星。雖然土星環非常龐大，卻只有20來米厚，所以每隔14至15年當地球通過土星環的平面時，環就會從望遠鏡的視野內消失。今年9月正是自伽利略觀測以來第27次土星環消失，現時更是觀測土星的好時機。
Galileo's anagram
It was a summer evening in 1610 when Galileo turned his telescope to Saturn. Surprisingly he did not see a single star but three (upper left of picture). To preserve his priority in claiming the discovery, he circulated an anagram, ‘smaismrmilmepoetaleumibunenugttauiras’, which actually stood for "I have observed the most distant planet to have a triple form." But in 1612 Galileo was puzzled to see no companion stars. It was not until 1616 that Saturn's ring was resolved by him. Although the ring is immense it is only about 20 meters thick. Every 14 to 15 years the earth would pass through the ring's plane and the ring would seem to have vanished. Now is the time to watch Saturn before its ring disappears again this September, for the 27th time. ■甄枝強 資深天文愛好者
|
放大圖片
