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Monday, November 23, 2009

Photo: Texas-Size Asteroid Slammed Early Mars, Studies Say


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As shown in an artist's conception, early Mars was likely hit by an asteroid wider than Texas that melted crust in the northern hemisphere, scientists say. The event flung crust into space while sending a shock wave through the planet's molten core (inset).

Such an impact is the best explanation for why Mars's crust in the north is significantly thinner than the crust in the south, according to three new studies.

Image courtesy Jeff Andrews-Hanna; inset courtesy Francis Nimmo.