Astronomy September 2009

The day Earth came to life
At some point in the dim past, non-living matter started to replicate itself. Scientists are still trying to figure out how.
By James Trefil and Wanda O'Brien-Trefil

What revved up the galaxy's hyperfast stars?
Since 2003 astronomers have found 16 stars escaping the Milky Way's gravity. The slingshot could be our galaxy's central black hole.
By Ray Jayawardhana

A new day dawns for Hubble
Shuttle astronauts installed two new instruments, fixed two older ones, and upgraded the space telescope's gyroscopes and batteries.
By Richard Talcott

The stars that revealed the vastness of the universe
Cepheids are pulsating variable stars that astronomers use to measure cosmic distances. They remain at the heart of solving key cosmic riddles.
By Bruce Dorminey

Astronomy's 2009 Astroimaging Contest
Amateurs accepted the challenge and sent us these dazzling images.
By Michael E. Bakich

10 tips for beginning astroimagers
Use these techniques to produce celestial images you'll be proud to share with friends and relatives.
By Michael E. Bakich