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A PLANET'S HISTORY
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youth, they have long since outgrown it. Only by rummaging their past could we find evidence on the point, and this, distance both in time and space bars
us from doing. There is but one body into whose foretime career we could hope to peer with the slightest prospect of success—our own Earth.
Whether our Earth was ever hot enough at the surface to vaporize those substances which now form the Jovian