When mosquitoes brought West Nile virus to New York, all the papers said it was going to be the next big deadly epidemic (which, of course, it wasn’t). The day the news came out, I was in my garden in Pittsburgh, and a mosquito landed on my arm. I smacked it, then immediately thought, “Oh my god! West Nile virus!” So I ran inside and did something I hadn’t done since grade-school summer camp: I doused myself with insect repellant. Then I got a whiff of the fumes and remembered I just read an article saying insecticides cause Parkinson’s disease!

After years of warnings about the threat of global warming, its potential impact struck home in 2003 with an unexpected death toll from bouts of extreme weather.

After years of warnings about the threat of global warming, its potential impact struck home in 2003 with an unexpected death toll from bouts of extreme weather.

With eyes in the sky and precision-guided public-health foot soldiers on the ground, Pennsylvania is in the midst of another summertime battle against the West Nile virus and the mosquitoes that bear it. Like other states, Pennsylvania uses rainfall data beamed from NASA satellites to guide mosquito control teams, but this season the Keystone State is taking its space-based surveillance efforts to a new level. In a new pilot program, NASA and state public-health authorities are using eight NASA earth science satellites to gather up-to-the-minute information not only on precipitation but on