By Laura Geggel - Live Science
By Rachael Rettner - Live Science
By Rachael Rettner - Live Science
By Rachael Rettner - Live Science
By Kim Ann Zimmermann - Live Science
By Laura Geggel, Associate Editor - Live Science
By Rachael Rettner, Senior Writer - Live Science
By Rachael Rettner, Senior Writer -Live Science
By Rotem Petranker, York University, Canada; and Thomas Anderson, University of Toronto - Live Science
By Rachael Rettner, Senior Writer - Live Science