The document provides an overview of Earth's atmosphere and how it protects the planet, as well as examples of meteor impacts on Earth and their effects. It then discusses observations of other planets like Mars, Venus, Jupiter, and beyond, noting features of their atmospheres, moons, and other characteristics. The document concludes by mentioning the Kuiper Belt and discovery of thousands of small bodies orbiting beyond Neptune's orbit.
28. Atmosphere lets the visible sunlight in, but traps infrared radiation and prevents rapid cooling of the surface at nights
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31. "It will be possible to see cities on Mars, to detect navies in [its] harbors, and the smoke of great manufacturing cities and towns... Is Mars inhabited? There can be little doubt of it ... conditions are all favorable for life, and life, too, of a high order. Is it possible to know this of a certainty? Certainly." Samuel Leland 1895 Seasons on Mars? Channels for irrigation ???
65. The Kuiper Belt – home for short-period comets?? Starting in 1992, astronomers have become aware of a vast population of small bodies orbiting the sun beyond Neptune. There are at least 70,000 "trans-Neptunians" with diameters larger than 100 km in the radial zone extending outwards from the orbit of Neptune (at 30 AU) to 50 AU.