By Ron Cowen
Imagine if Earth nearly touched the sun. It would take only one day for our planet to whip around the entire star, and Earth’s surface would be hot enough to melt iron. That may sound like a hellish situation for a terrestrial planet, but if theorist Doug Lin is right, the heavens might be riddled with such orbs.
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Of the more than 130 extrasolar planets identified so far, the smallest has been the size of Neptune, about 20 times the size of Earth. Lin, of the University of California, Santa Cruz, predicts a host of smaller planets, similar in mass to Earth but far higher in temperature.