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Chap. 18 Vocabulary
Astronomy
Term | Definition |
---|---|
Astronomy | The study of the universe |
Year | The time required for the Earth to orbit once around the sun |
Month | A division of the year that is based on the orbit of the moon around the Earth |
Day | The time required for Earth to rotate once on its axis |
Telescope | An instrument that collects electromagnetic radiation from the sky and concentrates it for better observation |
Refracting Telescope | A telescope that uses a set of lenses to gather and focus light from different objects |
Reflecting Telescope | A telescope that uses a curved mirror to gather and focus light from distant objects |
Electromagnetic Spectrum | All of the frequencies or wavelengths of electromagnetic radiation |
Constellation | A region of the sky that contains a recognizable star pattern and that is used to describe the location of objects in space |
Zenith | The point in the sky directly above an observer on Earth |
Altitude | The angle between an object in the sky and the horizon |
Horizon | The line where the Earth and the sky appear to meet |
Light-year | The distance that light travels in one year; about 9.46 trillion kilometers |