| 1. | Molecular clouds play an integral role in the prestellar evolutionary sequence of interstellar matter .
分子云在星际物质的星前期演化序列中起着不可缺少的作用。 |
| 2. | A star is formed when a cloud of gas collapses from the interstellar medium toward high density .
一个气体云自星际物质中坍缩，密度达到很高时，即形成了一个恒星。 |
| 3. | We observe in the galaxy much larger, denser, and more massive aggregates of cold interstellar matter .
在银河系中还观测到大小，密度和质量都要大得多的冷星际物质团。 |
| 4. | Without exaggeration we would claim that the problem of the condensation of interstellar matter into stars is only now being placed on a firm scientific footing .
我们可以毫不夸张地说，星际物质凝聚成为恒星的问题只是到了今天才有了坚实的科学基础。 |
| 5. | It also means that the comet is not made of small , pristine interstellar materials either
这同样也表示彗星不是由少量、原始星际物质构成的。 |
| 6. | If the cloud is visible , we call it a nebula . an example is the eagle nebula below
，假若这些星际物质可以看得到，我们便称之为星云，下图是著名的鹰星云： |
| 7. | Not volcanoes . the in - fall of massive objects onto the surface of the moon creates those craters
其实月面上的山不是山，而是由巨大星际物质撞击月面时所形成的 |
| 8. | Today , the crab nebula is still expanding and it will eventually dissolve in the interstellar gas cloud nearby
蟹状星云仍然在膨胀最终会溶入星际物质而消散。 |
| 9. | These filaments reveal where the shock wave is encountering lower - density , more uniform interstellar material
纤维揭示的是激波与更均匀的低密度星际物质相遇的地方。 |
| 10. | The outer layers of the star crashed into the interstellar medium , driving a shock wave that is still visible today
这颗星的外层撞到星际物质，由其产生的冲击波至今仍然可见。 |
