a spacecraft with the purpose of cricling around a celectial obejct without landing on it
轨道器, 轨道飞行器
科学家们使用月球轨道器来绘制月球的引力场。
the study of the movements of stars and planets that are thought to affect people and the world
占星学
占星术有着古老的根源，在世界各地的各种文化中都有实践，每种文化都有其自己的传统和解释。
an artificial object sent into space to orbit Earth or another celestial body, usually to collect or transmit information
all existing matter, energy, space, stars, planets, galaxies, and everything else that physically exists
宇宙, 天地
a large number of star systems bound together by gravitational force
星系
银河系是包含我们太阳系的星系，它是一个带有中央凸起和旋转臂的螺旋星系。
(astronomy) a shining point found in large numbers in the night sky
星星, 天体
a large, nearly round object in space that moves in an orbit around a star
行星, 星球
the large, bright star in the sky that shines during the day and gives us light and heat
太阳, 白昼之星
the sun and the group of planets orbiting around it, including the earth
太阳系, 太阳系
科学家研究太阳系以了解行星的形成。
the path an object in the space follows to move around a planet, star, etc.
轨道, 运行轨道
卫星被放置在一个稳定的轨道上，以从太空持续监测天气模式。
a vehicle designed to travel in space
航天器, 宇宙飞船
工程师们在将航天器送往外部行星执行任务之前，彻底测试了其系统。
clothing used by astronauts while traveling in space
宇航服, 太空服
宇航服包括一个带有面罩的头盔，以保护宇航员的眼睛免受太空中强烈阳光的伤害。
A spacecraft designed to transport people or equipment between Earth and a space station or other celestial destination, typically capable of multiple trips
航天飞机, 太空船
NASA的太空航天飞机计划彻底改变了可重复使用的航天器。
a spacecraft that moves up by the force of the gases produced when the fuel burns
火箭
火箭从发射台升空，将一颗卫星送入地球轨道。
the universe regarded as an ordered and unified whole
宇宙, 寰宇
a US government agency responsible for space travel and the study of space
美国国家航空航天局（NASA）负责美国的民用太空计划。
NASA的火星车成功登陆火星表面，标志着行星探索的重大成就。
the circular object going around the earth, visible mostly at night
月亮, 地球的天然卫星
a piece of equipment by which the far objects, particularly those in space, are made clearly visible
望远镜, 天文望远镜
望远镜提供了月球表面的清晰视图。
someone who is trained to travel and work in space
宇航员, 航天员
宇航员在太空任务期间进行了关于微重力效应的实验。
a place in the space with such high gravity that pulls in everything, even light
黑洞, 黑孔
银河系中心的超大质量黑洞影响着附近恒星和气体云的运动。
(astronomy) the distance light travels in one year, equal to about 5.88 trillion miles or 9.46 trillion kilometers
光年
a pale band of light seen in the sky at night that contains the solar system and billions of other stars
银河, 银河系
在晴朗的夜晚，你可以看到银河横跨天空。
the layer of gases surrounding a planet, held in place by gravity
大气, 气体层
