| 1. | One astronomical unit equals the distance from the earth to the sun .
一天文单位等于从地球到太阳的距离。 |
| 2. | The convenient length unit for measuring distances between planets is the astronomical unit
在天文学上，太阳系内天体的距离惯用 |
| 3. | Recall that one astronomical unit is the average distance between the sun and the earth
来表示，一天文单位即太阳和地球的平均距离请参阅 |
| 4. | Pluto , the remotest planet in the solar system currently known , is about 80 astronomical units away from the sun
太阳系与行星太阳系目前最遥远的行星冥王星距离太阳约 |
| 5. | Astronomers believe that comets originate from the oort cloud which is located 5 , 000 to 100 , 000 astronomical units from the sun
天文学家相信彗星诞生于距离太阳五千至十万个天文单位的奥尔特云。 |
| 6. | It dwells in the kuiper belt at about 42 au away and moves around the sun every 288 years 1 astronomical unit the distance between the earth and the sun , about 150 million kilometers
据初步计算，这颗天体距离地球约4 2个天文单位个天文单位太阳和地球的距离，即约15亿公里，运行一周需时288年。 |
| 7. | From 12 to 14 may , this mysterious string of comet will pass earth at a mere 0 . 0735 astronomical unit i . e . 29 lunar distances . astronomers expect that the biggest fragment will shine as bright as magnitude 5
5月12至14日，这串神秘的彗星会于地球0 . 0735天文单位即地月距离的29倍外掠过，天文学家预测它最大的碎片会亮至5等。 |
