Two Apollo 11 astronauts question NASA's planetary safety procedures.
Devil facial tumor disease, or DFTD, has cut the Tasmanian devil population by 90 percent. Now, some devils have evolved to resist the virulent cancer.
It's been 100 years since the world's last deadliest flu pandemic. Experts warn that another one is inevitable, but are we ready?
Antidepressants are destroying underwater ecosystems, which we in turn eat.
Dr. Larry Brilliant played a key role in eradicating smallpox from the world – so what are the biggest dangers humanity faces now? Brilliant rates politics as on-par with infectious disease.