A tag is a keyword or label that categorizes your question with other, similar questions. Using the right tags makes it easier for others to find and answer your question.

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Questions about observation performed in the radio frequency range of the electromagnetic spectrum (between 10 MHz and 1GHz).
Tag for questions asking if fictional ideas are possible or correct
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Questions related to the phenomenon whereby electromagnetic radiation (such as visible light) generated by an object moving away from an observer will have increased in wavelength (i.e. shifted toward…
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Questions about planets that do not orbit around a star. These planets travel through space.
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Questions regarding the action of or an object rotating along an axis.
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Questions regarding an object orbiting around another object due to the force of gravity.
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Questions about Saturn, the 6th planet in Earth's solar system.
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infinitely dense.
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Questions regarding the physical dimensions of a celestial object.
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Questions about computer programs that assist modeling and observing the dynamics of astronomy.
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Questions about the complete or partial blocking of the sun by the moon.
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Questions regarding the earthly Sun and objects orbiting it.
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Questions regarding the Sombrero Galaxy, also known as M104 or NGC 4594. It is an unbarred spiral galaxy, part of the Virgo constellation.
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The near-vacuum extending between the planets and stars, containing small amounts of gas and dust. Also called outer space to refer to the physical universe beyond the Earth's atmosphere.
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Space debris (also known as "orbital debris", "space junk", or "space waste") is the collection of defunct objects in orbit around Earth and includes everything from spent rocket stages, old satellite…
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Questions regarding a manmade object sent to explore space and celestial objects.
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Questions regarding telescopes in orbit around Earth, such as the Hubble Space Telescope.
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Questions regarding the 4-dimensional background structure of our universe.
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Questions regarding Albert Einstein's theory that posits, among other things, the equivalence of mass and energy.