A new autonomous robot can cruise underwater for seven months on a single battery charge.
He's the first African-American to head presidential ticket of a major party, winning Democrats' long war of attrition.
A greater focus on candidates' faith is generally applauded, but some cite reasons for caution.
Many understand, but some may doubt Obama's 'blackness.'
Microscopic organisms thrive in polar-ice 'brine channels' whose conditions mirror some of those found in space.