Where shall we go?
When I conceived
the idea for this web site, I was not familiar with a new discipline,
astrobiology. In the forefront of this discipline are two professors at the University
of Washington, Peter Ward, a paleontologist and Don Brownlee, an astronomer,
who have teamed up and written a book precisely what this web site is all
about: The Life and Death of Planet Earth. You can obtain a copy from Amazon.com.
I have read the
book, and it is one of the best books I have read. I have only one point on
which I disagree with the authors. Our technology is increasing in
sophistication at an exponential rate due mainly to computers. I am of course
optimistic and wish our species to survive which it can only do by leaving the
solar system for deep space. They
couldn’t conceive of a practical way to do it in terms of technology today.
However my answer to this problem is that I’m sure we’ll excavate the center of
our satellite, the moon, and transfer water and other necessities from our
dying planet and then take our new home into deep space.
In the interior,
we’ll be shielded from radiation as well as meteorites or comets which strike
the airless surface. With atomic or perhaps fusion power, we’ll be able to
voyage where we like and avoid the various dangers of deep space, but our
descendants will survive and continue learning.
We have evolved
into an articulate tool using animal.
In a few thousand years we have found extensions to each of our senses,
the most recent of which is our ability to think and remember. I don’t know if we are God's chosen or
even if there is a God, but we are the most developed of all of the species on
this planet and therefore have the responsibility to see that all of us
survive.
As I pointed out
in previous pages there are numerous dangers to the survival of all species on
this planet. Planets like stars are
born, have a life and then die. We have a choice, we can remain and die with our
birthplace, our beautiful home, or we can do as Noah did, we can build another
What this
I predict that we
will head for our nearest star neighbor, Alpha Centaurii, 3.6 light years
distance in the near future. With
our foreseeable technology we cannot achieve anything like the speed of light,
and we must be prepared for generations of our descendants to be able to exist
on such a trip. I will leave the
design of such vehicles to people much smarter than myself. The only thing which I'm sure it will
require, is an environment similar to our beautiful present planet.
Where shall we go?
I am sure we will go looking for a younger version of planet earth, circling a
younger star than our sun. Stars like planets are born, evolve and die, taking
their children, their circling planets with them. But yet I haven't spoken of the final
challenge.
Our universe with
its countless galaxies containing countless groups of stars was born some 15
billion years ago to the best of our knowledge. Some scientists believe what they call
the Big Bang theory. What was there
before the Big Bang no one ventures to say. Some say numerous black holes are
tunnels to other universes. Who
knows?
There is no doubt
that the Big Bang was a tremendous explosion and fragments were hurled in all
directions and are still going.
When the steam runs out, will this universe of ours begin to collapse into
another big bang? Who knows? If it does, by then our widespread emigration will
have been of no use, but I'm sure we have billions of years to prepare for it,
and our brightest minds must begin thinking about it.
I wish my
descendants a good trip wherever they go!
However we’re
already searching as the following article points out:
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If you
want to know where other Earth-like planets could survive, one way to find out
is to simply toss an Earth into an existing system where planets orbit a star
and see if it hangs in there or is tossed out.
That's what Barrie Jones and Nick Sleep did.
The researchers sorted through the handful of stars now known to
harbor nearly 100 planets altogether. Most of the planets are huge and very
close to their host stars, making it nearly impossible for Earth-sized planets
to exist in potentially habitable, Earth-like orbits. They would simply be
swallowed or tossed out of the system.
Jones and Sleep, of the Open University in
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"We had no particular expectations of the other
three," Jones said in an e-mail interview. "But in fact in all of
them, Earth-mass planets could be in stable orbits in at least some of each
habitable zone."
Why does any of this matter? Because hunting for planets the
size of Earth around other stars will be very difficult. Expensive next-generation
telescopes will barely be able to pull the task off. And there are lots of
stars out there, so knowing where to look could save a lot of time and money.
"Our work should identify the exosytems where one is more
likely to find 'Earths,' and so our work should help in target-selection,"
Jones said. "If no Earths are found in habitable zones where our work
indicates they could exist, then that should be of interest to people trying to
model the formation of exosystems."
The researchers will discuss their findings today the annual UK
National Astronomy Meeting. A paper on the early results of their work appeared
previously in the journal Astronomy & Astrophysics, and they are
preparing a new paper on their full results.
The ultimate goal in searching for other Earths is, of course,
to then look for signs of life. So far, the other solar systems that have been
found look very much unlike our own. But most researchers agree that's probably
because technology only allows for the detection of large planets very near
stars. Over the next decade, most experts expect solar systems more similar to
our own are likely to be discovered.
But no one knows if those systems will support rocky planets
with stable atmospheres and moderate temperatures -- places like Earth.
And many other factors might play a role in supporting life.
As Jones points out, some researchers figure that shifting
crustal plates -- the things that cause earthquakes -- are needed to recycle
material and make life possible. A moon might be needed to stabilize a planet's
rotation and help avoid large changes in climate. "I'm not convinced that
this is essential," Jones said.
Others argue large outer planets, like Jupiter, are needed to
shield an inner planet from excessive comet bombardment. "But this is
conjectural," Jones maintains.
Regardless of the exact ingredients needed to make a habitable
planet, the new study does not promise a whole lot. Importantly, it is based on
a computer simulation, not on observations. Several assumptions were made in
regards to whether other solar systems can even form in the same manner as our
own.
"Our biggest assumption is that Earth-mass planets can form
in the exosystems," Jones said. "Studies by others are beginning to
show that this is possible, at least in some of the exosystems."
The system most like our own that Jones and Sleep looked at is
called 47 Ursae Majoris. The star is sun-like, though a bit older. It is hotter
and brighter, so its habitable zone is a little further out than the region
around our Sun that's considered able to support life, as we know it.
Two giant planets orbit the star 47 Ursae Majoris. The inner
one, a bit farther from the star than Mars is from our Sun, is about 2.5 times
as massive as Jupiter. The outer one is probably about the size of Jupiter.
Other planets may well exist in the system, but they can't be found with
current technology.
"It's certainly a system worth exploring for an earthlike
planet and for life," Jones said.
The computer simulations may prove more useful as more and more
planetary systems are found, and astronomers develop a greater need to winnow
down the best candidates for further study.
"I think we will shortly discover systems with the giants
further out, more like where Jupiter is in the solar system," Jones said.
"We will then see whether Earth-mass planets could exist in their
habitable zones."