Daily Roundup: August 19, 2011

This Planet May Be Your Last: Scientists studying possible scenarios regarding extraterrestrial life hypothesized that aliens may "preemptively destroy our civilization in order to protect other civilizations from us." Sierra Daily and Guardian

Beach Boys: In recent years, retreating sea ice has forced walruses to congregate on Alaskan shores in record numbers. New Scientist and Live Science

Case Closed: A mysterious orange "goo" that appeared along the shore of a remote village in Alaska has been identified as fungal spores. AP

Kangaroo Hop: Scientists sequenced the complete genome of the tammar wallaby. It's the third marsupial to have its DNA sequenced. Australian Life Scientist

New Moon: The moon may be 200 million years younger than previously thought, suggests a recent moon-rock analysis. Los Angeles Times and MSNBC

--Della Watson