Cows that consume feed, grass or water contaminated with radioactive iodine-131 can concentrate the element in their milk. Peter Elvidge/iStockphoto.com hide caption
Science
Thursday
A view of the Three Mile Island power plant near Harrisburg, Pa., site of the worst nuclear accident in U.S. history. In 1979, a reactor at the plant experienced a partial meltdown, but radioactive material never escaped containment. Bradley Bower/AP Photo hide caption
The facilities at the Fukushima Dai-ichi nuclear power plant were designed to withstand strong earthquakes and tsunamis, but not to the strength and size experienced on March 11. Air Photo Service/AP hide caption
Wednesday
Mike Barlow has been installing geothermal systems for 20 years. But he says a 30 percent federal tax credit is increasing the popularity of the systems for families with modest houses. Elizabeth Shogren/NPR hide caption
Tokyo Electric Power Co. Chairman Tsunehisa Katsumata (second from right) and other executives bow prior to a press conference at the company's headquarters in Tokyo on Wednesday. Kazuhiro Nogi/AFP/Getty Images hide caption
Red #40, Blue #1, Yellow #6 - a rainbow of food dyes. Josh Roulston/Flickr hide caption
Tuesday
In 1992, 28,800 rubber ducks were lost at sea. What happened to them is the subject of Donovan Hohn's book Moby-Duck. Jose Gil/iStockphoto.com hide caption
Monday
Wasabi plants, like these, in Fukushima prefecture were found to contain substantial amounts of radioactive iodine. C.K. Koay/Flickr hide caption
A Pennsylvania state trooper and plant security guards stand outside the closed front gate to the Metropolitan Edison nuclear power plant on Three Mile Island near Harrisburg, Pa., in 1979. Paul Vathis, File Photo/AP hide caption
Saturday
Nighthawks are known for their repeated "peent" call as they hunt for flying insects. Bill Bouton/Flickr hide caption