SUNSET: 
On the 40th Anniversary of Apollo 17
Forty years after the last human visitors departed the Moon aboard Apollo 17, space historian Andrew Chaikin talks about why we should return.
A Bizarro "Cometoid"
Is it a comet? Is it an asteroid? Astronomers aren't sure what to call 133P/Elst-Pizarro.
Radiation Dangers for Mars Astronauts Downgraded
An experiment onboard Mars Odyssey suggests that radiation isn't as big a concern for Mars astronauts as once thought.
