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either of the two times of the year when the sun reaches its farthest or closest distance from the equator
至日
a subdivision of a geologic period, characterized by distinctive and globally recognizable rock layers, fossils, and significant changes in Earth's climate and biota
纪元, 地质纪元
either of the two moments in a year when the Sun, in its apparent motion along the ecliptic, crosses the celestial equator, resulting in approximately equal periods of daylight and darkness worldwide
春分, 秋分
the time as measured at Greenwich, London, on the line of 0° longitude, used to calculate the time across the globe
格林尼治标准时间, 格林尼治平均时间
(of the moon) to gradually decrease in its visible illuminated surface as it progresses from full to new moon
减弱, 衰退
the second layer of earth's atmosphere composed of cool and warm layers of air
平流层的
the theory that adds the notion of time to that of a three-dimensional space
时空, 时空理论
relating to the path or motion of an object as it revolves around another object in space
轨道的, 与轨道相关的
a glowing cloud of gas and dust in outer space, often the result of a star explosion or formation
星云
(of the moon) to progressively display a larger illuminated section until it turns into a full moon
变大, 增大
a small celestial body that becomes visible as a meteor upon entrance into the atmosphere of the earth
流星体
a piece of rock coming from outer space that passes through the Earth's atmosphere, producing light
流星, 陨石
a disruption in earth's magnetic field caused by solar activity, resulting in variations that can impact electronic systems and communications on earth
磁暴, 地磁风暴
situated or occurring between stars or within the space that exists between stars
星际的, 星与星之间的
(physics) an invisible substance that makes up most of the universe's mass, detectable only through its gravitational effects
暗物质, 暗质
very small particles originally derived from stars, serving as raw material for forming planets, and existing between galaxies, stars, and other celestial bodies
宇宙尘埃, 星际尘埃
the outer layer of the Sun's atmosphere, observable as a plasma halo during a solar eclipse
日冕, 太阳的日冕
an object in space that is a mass of ice and dust and when it nears the sun it starts illuminating in the shape of a tail
彗星
the colored lights, mainly green and red, in the sky seen primarily near the southern magnetic pole
南极光, 南方极光
the colored lights, mainly green and red, in the sky seen primarily near the northern magnetic pole
北极光
a specific group of stars that form a pattern and have a name related to their shape
星座
a part of planet where the air, land, and water are suitable for all the living things to exist on
生物圈
