These are usually any sort of geometric lines that have only an abstract definition and do not physically exist.
Imaginary lines
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An invisible line around which an object rotates, or spins.
Earth’s axis
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The curved path of a celestial object around a star, planet, or moon, especially a periodic elliptical revolution.
Orbit
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A zone delimited by the imaginary circles that have characteristics such as climate, vegetation, fauna and precipitation.
Thermal zone
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An imaginary line drawn around the earth dividing the earth into northern and southern hemispheres and constituting the parallel of latitude 0°.
Equator
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The part of the Earth's surface between the Tropic of Cancer and the Tropic of Capricorn; characterized by a hot climate.
Tropical zones
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Each of the two belts of latitude between the tropical zone and the northern and southern polar zones.
Temperate zone
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The weather conditions prevailing in an area in general or over a long period.
Climate
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Imaginary line extending around the Earth parallel to the equator; it is used to indicate latitude.
Parallel
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It is the one that the Earth accomplishes around the Sun. It describes an elliptical orbit.
Translation
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A year, occurring once every four years, that has 366 days including February 29 as an intercalary day.
Leap year
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The season after winter and before summer, in which vegetation begins to appear.
Spring
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The warmest season of the year, in the northern hemisphere from June to August
Summer
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The third season of the year, when crops and fruits are gathered and leaves fall, in the northern hemisphere from September to December.
Autumn
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The coldest season of the year, in the northern hemisphere from December to March.
Winter
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The time or date (twice each year) at which the sun reaches its maximum or minimum illumination, getting the longest and shortest days (about June 21 and December 22).