At low altitudes they help to cool the Earth by reflecting sunlight away from it.

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The scenery belies the relatively low altitudes, with great alpine hiking at just 2, 000m above sea level.

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They are most effective when fired at aircraft flying at low altitudes, as at take-off or landing.

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Base jumping sees participants launch themselves from a surface and free fall from predominantly low altitudes before opening a parachute.

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The authors report that glaciers are retreating everywhere in the tropical Andes, but the melting is more pronounced for small glaciers at low altitudes.

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When military planes flew past at low altitudes, the adult minks apparently became so frightened that they turned on their young and bit them to death.

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Synthetic vision systems were created by NASA and the U.S. Air Force back in the late 1970s to improve cockpit situational awareness, especially when operating in reduced visibility at low altitudes.

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The computer can correct the missile's course, enabling it to fly at very low, landscape-hugging altitudes, and follow a complicated route.

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Its four turboprops provide it with a cruise speed of 0.72 mach at altitudes of up to 40, 000 feet and the plane has excellent low speed handling characteristics needed for paratroopers and load dropping.

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