众所周知，天文学是一门古老的学科。随着科技的发展，人类对天体的认知亦越发深入！
Astronomy is the oldest science known to man.Thousands of years ago man looked at the stars and wondered about the heavens.But man was limited by the six planets that he could see with his eyes alone.The Greeks studied astronomy over 2，000 years ago.They could see the size，colour，and brightness of a star.They could see its place in the sky.They watched the stars move as the seasons changed.But the Greeks had no tools to help themselves study the heavens.Each new tool added to the field of astronomy helped man reach out into space.Until there were telescopes，man knew a little about the moon.He did not know that the planet called Saturn had rings around it.His sight was so limited that he could not see all the planets.Before the spectroscope，man did not know what kind of gases was around the sun or other stars.Without the radiotelescope，we did not know that radio noises came from far in space.Today，astronomy is a growing science.We have learned more in the last fifty years than in the whole history of astronomy.
[阅读障碍词]
1．tool n．工具
2．telescope n．望远镜
3．Saturn n．土星
4．spectroscope n．分光镜
5．radiotelescope n．射电望远镜
