• Mystery Methane Maker
    On Earth, methane is mostly produced by life. The recent detection of methane in the martian atmosphere therefore has given rise to much speculation about the possibility for life on the Red Planet. Part three of this four-part series investigates the most
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  • Methane on Earth
    On Earth, methane is mostly produced by life. The recent detection of methane in the martian atmosphere therefore has given rise to much speculation about the possibility for life on the Red Planet. In part two of this four-part series, the various ways
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  • Interplanetary Whodunit
    On Earth, methane is mostly produced by life. The recent detection of methane in the martian atmosphere therefore has given rise to much speculation about the possibility for life on the Red Planet. Part one of this four-part series about methane and Mars
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  • Earth's Oldest Fossils Reverse Course
    It's a critical question of life science: Are microscopic structures found in 3.5 billion-year-old Archean rocks from Western Australia the oldest fossils of life on Earth? That depends, says one scientist, on whether you think the rocks formed from above -- or below.
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  • Earth’s Oldest Fossils Reverse Course
    It's a critical question of life science: Are microscopic structures found in 3.5 billion-year-old Archean rocks from Western Australia the oldest fossils of life on Earth? That depends, says one scientist, on whether you think the rocks formed from above -- or below.
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  • Nanodiamonds are Forever? Maybe Not
    When nanodiamonds were discovered in 1989, they seemed to be remnants of supernovas - tiny grains of physical history even older than the solar system. Logically, comets should be full of these microscopic diamonds.
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  • Early Mars: Oceans Away?
    The surface of Mars is scarred by ancient river valleys, apparently carved by liquid water. But was Mars warm and wet continuously for millions of years - or only temporarily when massive asteroids slammed into it? The likelihood of life on Mars may depend on
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  • What Does ET Look Like from 40 Light Years Away?
    The Terrestrial Planet Finder (TPF) mission will have the technology to look for signs of life in the light reflected or emitted by planets orbiting nearby stars. But nobody knows exactly what signals life would emit. Clues from studies of Earth's early atmosphere are guiding
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  • Ancient Fossils – or Just Plain Rocks?
    How the 3.5 billion year history of Earth gets written depends on proposed fossilized bacteria found in rocks from Western Australia. If life did exist that early then biological beginnings predated significant atmospheric oxygen by about a billion years. The debaters have just
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  • Smoking Craters: Home to Martian Life?
    Mars may be smaller than Earth, but it's still huge to a roving spacecraft that can cover only 100 meters a day. For that reason, Mars mission planners must go to great lengths to find landing sites that might still carry evidence that life once
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