When you look at the sky at night, you may see a comet(彗星) moving and shining. A comet looks like a star. A comet has no light of its own. It shines with reflecting(反射) sunlight.
Like the earth, a comet goes round the sun, but on a much longer path than the earth travels. A large part of a comet is water frozen into pieces of ice and mixed with iron and rock dust.
An Englishman named Edmund Halley found out a lot about the paths that comets take through the sky. Some comets move out of our sight and never come back. Others keep coming back at regular times.
A big comet that keeps coming back was named after Halley because he was the one who found it would come back again. Maybe you have ever seen Halley’s Comets because the last time it came close to the sun and the earth was in the year 1986. Then people all over the world were outside at night to look at it. You will probably be able to see Halley’s Comets when it comes near the earth again.
本时文内容由奇速英语国际教育研究院原创编写，未经书面授权，禁止复制和任何商业用途，版权所有，侵权必究！（投稿及合作联系：028-84400718 QQ：757722345）
更多优质学习内容
