It seems inevitable that humans are going to Mars, but unless they figure out the radiation problem, all that preparation will be moot.
The space agency is considering an artificial magnetic field around the planet to defend against harmful radiation from the sun.
The greatest ozone-depleted area in the world beside the one over Antarctica runs along the Peruvian Andes.
Greenpeace tests show overall contamination from key isotopes has fallen somewhat, but lingers, especially in places such as forests.
"I've had a wonderful life. I've got thousands of friends," the 90-year-old former president says.
A 54 centimeter robot with a scorpion-like tail will be sent inside one of Fukushima's reactors this August.
Security measures adopted to stop pets being used for smuggling as owners raise concerns over radiation threat.
The massive earthquake and tsunami that hit on March 11, 2011 killed more than 15,000.
New radiation-shielding briefs may just save your sperm