Two polar bears spar on the shoreline of the Hudson Bay in November 2007.
Credit Paul J. Richards / AFP/Getty Images
Federal agents interviewed new witnesses this week in an ongoing investigation of government scientists that's been called "polar bear-gate," according to the scientists' lawyer.
The controversial probe, now entering its third year, is looking into allegations of scientific misconduct related to a 2006 report by wildlife researchers Charles Monnett and Jeffrey Gleason, who described seeing dead polar bears floating in Arctic waters.
This NASA map shows the size of aerosol particles in the atmosphere. Green areas indicate larger, more naturally occurring particles like dust. Red areas indicate smaller aerosol particles, which can come from fossil fuels and fires. Yellow areas indicate a mix of large and small particles.