by Adam Smith
June 15,
2020
from
TheIndependent Website
Spanish version
New
calculations could shed light
on the fate of
our own species and planet...
There could be more than 30
alien civilizations in our galaxy,
researchers have found in a major study.
A new paper (The
Astrobiological Copernican Weak and Strong Limits for Intelligent
Life) looked to understand how many planets in our
neighborhood could be home to alien life, by assuming that life
develops on other planets in a similar way to how it develops on
Earth, and matching that to planets that could be home to similar
evolution.
It found that there could be dozens of active civilizations waiting
to be found in our Milky Way.
But it could also shed
light on our own fate, and suggest our prospects for long-term
survival are lower than we may have thought.
"There should be at
least a few dozen active civilizations in our Galaxy under the
assumption that it takes 5 billion years for intelligent life to
form on other planets, as on Earth," Christopher Conselice of
the University of Nottingham said in a statement.
"The idea is looking at evolution, but on a cosmic scale. We
call this calculation the Astrobiological Copernican Limit."
The Astrobiological
Copernican limits come in two forms.
One is the 'Weak'
limit, which suggests that intelligent life forms on a planet
any time after 5 billion years.
The other is the
'Strong' limit where life formed between 4.5 billion and 5
billion years years ago.
The new research used the
latter, and also assumed that these new species would need to
develop in metal-rich environments.
This is because human
beings developed near a metal-rich environment, due to the metal
present in
the Sun.
Previous research from 2012 suggests a suitable "minimum stellar
metallicity" required for the formation of planets that would be
similar to Earth.
Researchers were then able to use those assumptions about where
life (similar to ours) may form to understand how many
planets in our Milky Way would be able to satisfy those
conditions.
Detecting any
civilizations in our galaxy is strongly dependent on how well we can
pick up signals being sent into space.
These include radio
transmissions from satellites and television.
If these technological
civilizations last as long as ours, which has been sending out
signals for the last century or so, then it is estimated there could
be 36 ongoing intelligent civilizations.
While that might be the case, interacting with them would be
difficult. The average distance to any possible civilization would
be 17,000 light years, which makes communication very
challenging.
The other scenario is that we are the 'only' intelligent life in
the galaxy (sic), and that civilizations die out before we can
detect them.
"Our new research
suggests that searches for extraterrestrial intelligent
civilizations not only reveals the existence of how life forms,
but also gives us clues for how long our own civilization will
(could) last," Professor Conselice said.
"If we find that
intelligent life is common then
this would reveal that our civilization could exist for much
longer than a few hundred years, alternatively if we find that
there are no active civilizations in our Galaxy it is a bad sign
for our own long-term existence.
By searching for
extraterrestrial intelligent life - even if we find nothing
- we are discovering our own future and fate."
The new study (The
Astrobiological Copernican Weak and Strong Limits for Intelligent
Life) was led by the University of Nottingham and
published today in The Astrophysical Journal.
This is not the only recent news to imply the development of
intelligent life in the galaxy.
Scientists have found a potential habitable planet called 'Proxima
b' around the star
Proxima Centauri, approximately 4.2
light years from the Sun.
It receives comparable amounts of energy to that the Earth gets from
the Sun.
If there is liquid form
on the planet, it could harbor 'life' (like ours), but
researchers said there is still much to be done before that can be
confirmed, such as checking for the atmosphere and chemicals that
could support life.
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