The skin is the largest organ of the body, and helps protect it from the environment.
One of the most active volcanoes on Earth, Hawaii's Kilauea has erupted continually for more than 30 years.
A study by the Pew Research Center shows that the total number of Catholics in the world has tripled in the past century.
A study by the United Nations shows that U.S. life expectancy is years shorter than in many other countries.
More than half of the continental United States this summer is experiencing moderate to extreme drought, according to reports released by the National Weather Service.
Sixteen countries rank as the Worst of the Worst in personal freedoms, with 23% of the world population having no say in how they are governed.
The 20th century saw big strides in defeating many illnesses, but heart disease and cancer are still the major causes of death in the United States.
Wreckage from the earthquake and tsunami that devastated Japan in 2011 has traveled thousands of miles across the Pacific Ocean.