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For many people, the main question about extra-terrestrial life
is whether or not it exists. To much of the scientific community, however, that
question has already been answered: It does. And it's probably within our own
solar system. The scientists who believe in extraterrestrial
life are staking their careers, research funds, and prestige that they're right.
Institutions are doing so as well -- NASA has its Institute of Astrobiology, the
University of Washington its Department of Astrobiology. Their high-stakes gamble
is giving rise to a new science of life on other worlds. Meanwhile,
the pace of discovery in astrobiology has been absolutely breathtaking. The list
of major new findings includes:
- The discovery
of extremophiles -- microbes that inhabit extremely unfriendly environments --
which greatly expands the range of places where life could exist;
- The
discovery that extremophiles may have been Earth's earliest life;
- The
discovery that life appeared on Earth almost as soon as the surface was cool enough
for liquid water -- suggesting that life gets started relatively easily;
- The
discovery of water on Mars and liquid oceans on moons of Jupiter;
- The
discovery of far more extrasolar planets than anybody expected even five years
ago.
These discoveries all point in one direction:
Life is easier to start up, inhabits a greater range of environments, and has
many more possible sites than we once thought. There seems to be little doubt
that it's common in the universe and that finding it is only a matter of time. What
next? That's where things get interesting, and what Life Everywhere is
all about. How are we going to create a science of astrobiology? What do astrobiologists
want to know? Extraterrestrial life is hugely important, not for the simple fact
of its existence but for what it can tell us about life everywhere. Once scientists
have more than one example to look at, they can begin to understand the evolution
of life on Earth. They can learn which aspect of Earth's history are one-of-a-kind
accidents and which ones arise from broad principles governing the emergence and
rise of life generally. In Life Everywhere, David Darling talks with all
the major players in the field and shows how they're dealing with such questions
as: - What ultimately defines life?
- What
conditions give rise to life, and how often are they met?
- How
does evolution really work?
- How often do complex
life-forms arise from simple ones?
- How often does
intelligence arise?
The discovery of life on
other planets will be one of the great turning points of human history. Life
Everywhere tells us why many scientists think that discovery is inevitable,
and what they think we will learn from it. David Darling
has a B.Sc. in physics from Sheffield University and a Ph.D. in astronomy from
the University of Manchester, England. He lectures widely and is the author of
about forty science books for adults and for children. He lives in Brainard, Minnesota. |
