1.
The seasons change fast and it have passed more than 15 years in a twinkling.
斗转星移，转眼间又过了15年。
2.
The seasons change fast and 15 years more have passed in a twinkling.
斗转星移， 转眼间又过了15年。
3.
A natural satellite revolving around a planet.
（行星的）卫星围绕行星运转的天然卫星
4.
A binary star is a double star, consisting of two stars turning round each other.
双星是两颗星，是由相互围绕旋转的两颗星组成。
5.
narrow-band active repeater satellite
窄频带有源转发卫星
6.
A whirling couple of weeks passed.
转眼过了两个星期。
7.
epicyclic reduction gear star type
定星式周转减速齿轮
8.
epicyclic reduction gear solar type
恒星式周转减速齿轮
9.
Communication Satellite Relay Service
卫星通信中转业务公司
10.
There are nine planets going round the sun.
九颗行星围绕太阳运转。
11.
The planets revolve around the sun.
行星绕着太阳运转。
12.
Structure of a pulsar- a rotating magnetic neutron star.
脉冲星的结构。一颗旋转磁中子星。
13.
binary star (two stars that revolve around a common centre)
双星（环绕一共同中心旋转的两颗星）.
14.
The satellite slowly rotates as it circles the Earth.
卫星在绕地球旋转的同时缓慢地自转。
15.
All the eight planets go round the sun the same way. Each of them also turns of its own axis.
八大行星都围绕太阳运转，每个行星也绕着自转轴自转。
16.
The planet is probably in orbit around a small star.
这颗行星可能在围绕着一颗小恒星运转。
17.
Pulsar: A dense, rapidly rotating star that emits pulses of light.
脉冲星：高密度、快速旋转、发射脉冲光的星体。
18.
However, Neptune does not turn on its side the way Uranus does.
然而，海王星不像天王星那样朝一边倾斜旋转。