Scientists warn that even small asteroids that explode in earth's atmospher pose a threat because they could be mistaken as a nuclear weapon explosion by countries that lack the technology to tell the difference. They point to a June 6th incident that could have created a miscalculation during a tense period in the India/Pakistan conflict.
Humans could venture to Mars in 20 years or less, NASA chief Daniel Goldin said, in comments that made orbital space flight sound positively last century.
New research indicates that black holes may be the force behind half the energy released since the universe began.