The oldest assemblages of stars in the galaxy are

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The oldest assemblages of stars in the galaxy are believed to be the _____________ clusters. xplanation: Globular. Ages for globular clusters are now variously estimated at anywhere from ten to twelve billion years old. Globular clusters are composed of population II stars. The fragmentation and vaporization of a meteorite upon entering the atmosphere is called _____________. Explanation: Ablation. As a meteoroid plunges into the Earth's atmosphere at a speed of many miles per second, it undergoes many collisions with air molecules. The impinging molecules penetrate the meteoroid and chip off pieces of it. The surface of the meteoroid heats up and the dislodged particles vaporize. The fraction of incident light that is reflected by a body is called its ____________. Explanation:
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Albedo. The moon's albedo is about 0.07, which means that it reflects only about 7% of the light from the sun. It absorbs most of the sunlight. Visible light is the range of electromagnetic ______________ that is detectable by the human eye. Explanation: Radiation. Radiation is a general term for energy emitted as particles or waves; if you look at the graphic below, you will see that visible light is just one small part of the electromagnetic spectrum: Optical astronomers use optical telescopes, such as the refracting and reflecting telescopes you learned about, to study stars based on the visible light they emit. In the 1930s, another approach to "observing" the stars was discovered, using __________ telescopes. Explanation: Radio. The sun and most stars release most of their radiation in the visible light spectrum. However, some objects actually emit a lot more radiation at the radio wavelengths than at those of visible light. Therefore, while they might be too dim to detect with optical telescopes, they're very "bright" when seen with a radio telescope.
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The ____________ form of electromagnetic radiation that exists is radio waves. Explanation: Longest. This leads to one of the biggest advantages of radio telescopes versus optical telescopes. A lot of times, interstellar dust grains that would be big enough to block a visible light wave would not affect a radio wave, which has a much longer wavelength. Radio telescopes allow us to probe dusty regions of space, such as nebulas, and observe the birth of stars, which are heavily shrouded in dust and impossible to penetrate with an optical telescope.
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Also, as mentioned in the previous question, some objects emit more radiation in the radio wavelengths than in the visible light wavelengths. Pulsars are probably the biggest example--a lof of pulsars are not detectable by their light, but rather by their radio emissions. __________ rays have the shortest wavelength on the electromagnetic spectrum, having no defined lower limit to their wavelength. Explanation: Gamma. Astronomers could not begin observing the presence of gamma rays in the universe until the 1960s, because most gamma-rays are absorbed by the Earth's atmosphere. It wasn't until astronomers were able to put a gamma-ray telescope in space, outside of the influence of our atmosphere, that they were finally able to begin collecting data.
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