Crystals: Mark A. Schneider/Photo Researchers, Inc.
Water Wonders Loads of critters live in a scoop of seawater. These wee creatures are in trouble. Find out how acid waters may wipe out the smallest animals in Earth's oceans.
On Thin Ice Earth is heating up. That means trouble for animals in the Arctic. Global warming could erase their entire, amazing habitat. Travel to the top of the world on page 10 of our Nov.-Dec. 2007 issue to learn why Arctic animals are on thin ice.
Crystals There is an amazing cave in Mexico with crystals as long as telephone poles. How did the crystals get so big? What stories can these rock stars tell about Earth? Go rock hunting with a geologist on page 16 of our Nov.-Dec. 2007 issue to find out.
