An anonymous reader notes the discovery of a 35-million-year-old impact crater in the Timor Sea
, northwest of Australia, which helped to usher in a period of significant global cooling. "The new findings, announced today and published in the Australian Journal of Earth Sciences, suggest that the impact could have contributed towards the formation of the Antarctic ice sheet... The minimum size of the dome, which 'represents elastic rebound doming of the Earth crust triggered by the impact' is 50 km across, but the full size of the crater could be significantly larger, [lead researcher Andrew Glikson] told Australian Geographic. 'It would be possibly 100 km.' From the probable diameter of the crater, Andrew estimates that the asteroid which struck the Timor Sea was between 5 and 10 km in size. This impact coincided with a time of heavy asteroid bombardment globally. Several other craters have been documented from a similar time, including one off the WA coast measuring 120 km in diameter. Another impact structure in Siberia was created by an asteroid 100 km in size."