- ASTRONOMY -
1. Asteroid n.小行星 adj.星状的
any one of the many small planets which go around the sun
asteroid belt 小行星带
binary asteroid 双小行星
2. Axis n.轴;轴心国
an imaginary line through the centre of an object, around which the object turns
The Earth spins on its own axis.
3. Big Bang n.宇宙大爆炸(一种关于宇宙起源的学说)
the idea that the universe began with a single large explosion (the ‘big bang’), and that the pieces are still flying apart.
4. Black hole n. 黑洞
an area in space that nothing, not even light, can escape from, because gravity is so strong there.
5. Comet n.彗星
a mass of ice and dust that moves around the sun and looks like a bright star with a tail
Halley's Comet is going to come back in 2061.
6. Constellation n. 星座
a group of stars that forms a shape in the sky and has a name
7. Cosmos 宇宙
the universe, especially when it is thought of as an ordered system
our place in the cosmos
the structure of the cosmos
8. Dark matter n. 暗物质
according to some theories, material which exists in space that does not produce any light 暗物质（根据一些理论，指太空中不发光的物质）
9. Ellipse n.椭圆
a regular oval shape, like a circle that has been squeezed on two sides; shape of planetary orbits
The Earth orbits in an ellipse.
10. Equinox n.春分，秋分，昼夜平分点
one of the two times in the year (around 20 March and 22 September) when the sun is above the equator and day and night are of equal length
In the Chinese calendar, the Spring Equinox always occurs in the second month.
11. Galaxy n.银河;星系
any of the large systems of stars, etc. in outer space
the Milky Way 银河的比喻用法
Astronomers have discovered a distant galaxy.
12. Light year n. 光年
the distance that light travels in one year, 9.4607 × 1012 kilometres, used for measuring distances between stars（光年是距离单位哦~）
13. Meteor 流星
a piece of rock from outer space that makes a bright line across the night sky as it burns up while falling through the earth's atmosphere
a meteor shower 流星雨
14. Nebula n.星云
a mass of dust or gas that can be seen in the night sky, often appearing very bright
They were near a dark-matter nebula.
15. Gravity n.重力
the force that attracts objects in space towards each other, and that on the earth pulls them towards the centre of the planet, so that things fall to the ground when they are dropped
Newton's law of gravity 牛顿万有引力定律
16. Orbit n./v.轨道;绕…作轨道运行
a curved path followed by a planet or an object as it moves around another planet, star, moon, etc.
A new satellite has been put into orbit around the earth. 一颗新的人造卫星被送上了环绕地球的轨道。
17. Rotation n.自转;旋转
the action of an object moving in a circle around a central fixed point
the daily rotation of the earth on its axis
18. solar eclipse 日蚀
when the Moon passes between the Sun and the Earth
When is the next solar eclipse?
19.Lunar eclipse 月蚀
In a lunar eclipse, Earth passes between the sun and the moon.
20. Solstice n.至;至点
来自于古拉丁语“point at which the sun seems to stand still”，字面意思即太阳停止的地方。
either of the two times of the year at which the sun reaches its highest or lowest point in the sky at midday, marked by the longest and shortest days
Summer solstice 夏至
Winter solstice 冬至