萬物簡史 第31期:走進太陽系(9)

　　So the solar system is really quite enormous. Bythe time we reach Pluto, we have come so far thatthe Sun—our dear, warm, skin-tanning, life-givingSun—has shrunk to the size of a pinhead. It is littlemore than a bright star.

　　所以，太陽系確實是巨大的。當我們抵達冥王星的時候，我們已經(jīng)走得那么遙遠，太陽--我們那暖暖和和、曬黑我們皮膚、賦予我們生命的親愛的太陽--已經(jīng)縮小到了針尖大小。它比一顆明亮的恒星大不了多少。

　　In such a lonely void you can begin to understandhow even the most significant objects—Pluto's moon, for example—have escaped attention. Inthis respect, Pluto has hardly been alone. Until the Voyager expeditions, Neptune was thoughtto have two moons; Voyager found six more. When I was a boy, the solar system was thoughtto contain thirty moons. The total now is "at least ninety,"about a third of which have beenfound in just the last ten years.

　　在這樣冷清清的空間里，你會開始理解，為什么即使是最重要的物體--比如冥王星的衛(wèi)星--也逃過了人們的注意力。在這方面，絕不只是冥王星。在"旅行者"號探險之前，人們以為海王星只有兩顆衛(wèi)星，"旅行者"號又發(fā)現(xiàn)了6顆。在我小時候，人們以為太陽系只有30顆衛(wèi)星?，F(xiàn)在的衛(wèi)星總數(shù)至少已經(jīng)達到90顆，其中起碼三分之一是在剛剛過去的10年里發(fā)現(xiàn)的。

　　The point to remember, of course, is that when considering the universe at large we don'tactually know what is in our own solar system.

　　在考慮整個宇宙的時候，你當然需要記住，我們其實還不知道我們太陽系的家底。

　　Now the other thing you will notice as we speed past Pluto is that we are speeding past Pluto. Ifyou check your itinerary, you will see that this is a trip to the edge of our solar system, andI'm afraid we're not there yet. Pluto may be the last object marked on schoolroom charts, butthe system doesn't end there. In fact, it isn't even close to ending there.

　　現(xiàn)在，當我們飛越冥王星的時候，你會注意到另一件事：我們在飛越冥王星。要是你查一查旅行計劃，你會明白這次旅行的目的地是我們太陽系的邊緣，我們恐怕還沒有到達。冥王星也許是標在教室掛圖上的最后一個物體，但太陽系并不到此為止。實際上，離終點還遠著呢。

　　We won't get to the solar system's edge until we have passed through the Oort cloud, a vastcelestial realm of drifting comets, and we won't reach the Oort cloud for another—I'm so sorryabout this—ten thousand years. Far from marking the outer edge of the solar system, as thoseschoolroom maps so cavalierly imply, Pluto is barely one-fifty-thousandth of the way.

　　要到達太陽系的邊緣，我們非得穿過奧爾特云，那是個彗星飄游的茫茫天際。而我們--我為此感到很遺憾--還要再花1萬年時間才能抵達奧爾特云。冥王星遠不是太陽系外緣的標志，就像教室里的掛圖上隨便暗示的那樣，它僅僅是在五萬分之一路程的地方。