NASA has also put up a Q&A on this comet:
http://www.jpl.nasa.gov/news/news.cf...lease_2011-255
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So you've got a modest-sized icy dirtball that is getting no closer than 35 million kilometers [about 22 million miles)," said Yeomans. "It will have an immeasurably minuscule influence on our planet. By comparison, my subcompact automobile exerts a greater influence on the ocean's tides than comet Elenin ever will."
Cheers -