The term "peer-to-peer" has come to be applied to networks that expect end users to contribute their
own files, computing time, or other resources to some shared project. Even more interesting than the
systems' technical underpinnings are their socially disruptive potential: in various ways they return
content, choice, and control to ordinary users.
Humankind’s fascination with Mars predates
recorded history. The bright planet with the reddish tint
is unique among the other celestial objects. Tycho
Brahe’s observations of its unpredictable motion were
deciphered by Johannes Kepler in the early 17th century
as he developed his laws of planetary motion.
Galileo trained his telescope on Mars and saw it as a
disk in 1610. Later in the 1600s, Christiaan Huygens
and Gian Cassini drew the first maps of the Martian
Curiosity is in his title.John Grotzinger, NASA’s Curiosity project manager,
has a pretty cool job. He gets to direct the research efforts of NASA's Curiosity
rover. He and his team have already demonstrated evidence of liquid water
on ancient Mars, and they are now in hot pursuit of measurable methane[U1]
on the planet. Even if Grotzinger’s team find methane—and convincingly
confirm that finding—it still won’t be unequivocal evidence of microbial life.
But it will be tantalizing enough that their next step will be to focus on tracking
down the source.