探索频道 Cosmos 宇宙的边疆04
(I wonder) how many planets and how many civilizations might be destroyed.
In the Pegasus Cluster there is a ring galaxy, the wreckage left from the collision of two galaxies, a splash in the cosmic pond. Individual galaxies may explode and collide and their constituent stars may blow up as well. In this supernova explosion a single star outshines the rest of its galaxy. We are approaching what astronomers on Earth call the Local Group.
3 million light years across, it contains some twenty galaxies. It's a sparse and rather typical chain of islands in the immense cosmic ocean. We are now only two million light years from home. On the maps of space, this galaxy is called M31, the great galaxy Andromeda. It's a vast storm of stars and gas and dust. As we pass over it, we see one of its small satellite galaxies. Clusters of galaxies and the stars of individual galaxies are all held together by gravity.
Surrounding M31 are hundreds of globular star clusters. We are approaching one of them. Each cluster orbits the massive centre of the galaxy, some contain up to a million separate stars. Every globular cluster is like a swarm of bees bound by gravity -- every bee, a sun. From the Pegasus Cluster, our voyage's taken us 200 million light years to the Local Group dominated by two great spiral galaxies.
Beyond M31 is another very similar galaxy, its spiral arms slowly turning once every quarter billion years. This is our own Milky Way seen from the outside.This is the home galaxy of the human species.
In the obscure backwaters of the Carina-Cygnus spiral arm, we humans have evolved the consciousness and some measure of understanding. Concentrated in its brilliant core and strewn along its spiral arms are four hundred billion suns. It takes light a hundred thousand years to travel from one end of the galaxy to the other. Within this galaxy are stars, worlds and it may be an enormous diversity of living things and intelligent beings and space faring civilizations.
the Pegasus 【天】飞马星座
supernova n.[天]超新星
Andromeda n. 仙女座
globular adj.球状的
backwater n.逆流
Carina [拉][天]船底(星)座
Cygnus n.[天] 天鹅座
- 频道推荐
- |
- 全站推荐
- 推荐下载
- 网站推荐
