Ask A Scientist© Biology Archive

Question:  Is there any possibilities for people to travel or live in other planets?
Barry A Bieda

Answer:
   Travel to other planets in our own solar system is routine but long and
pricey ($millions per months-long trip) for robots.  It could be routine
for a small number of humans too but would cost right now a lot, maybe
5-10% of what the world spends on weaponry and loads more than it spends on
infectious disease prevention.  Travel to planets outside the solar system
is limited by the very large distances involved (which light typically
takes decades to centuries to cross) and the lack of a roadmap.  With
Apollo rocket technology it would take 40,000 years or so to reach the
nearest star, and we don't know if it has planets anyway.  It's difficult
to imagine advances in propulsion technology sufficient to reach speeds
near light, or extensions in human longevity (not to mention patience) or
"hibernation" abilities to centuries, so interstellar travel within one
lifetime is hard to imagine (which does not, of course, mean it can't be
done anyway).  Opinions vary, but I'd say the major hurdle to
large-distance space travel by human beings is achieving a consensus among
people and nations that it's something worth spending lots of money and
time on. Twenty-five years ago that consensus was partially achieved, for a
variety of reasons, whereas today it seems essentially absent.
   Living by large numbers of people on other planets in our solar system
comfortably would be at present impossible, as none has enough breathable
air, comfortable gravity, and a temperature tolerable in ordinary clothes.
Nevertheless one can easily imagine small numbers of people living in
carefully enclosed  spaces (domes, sealed buildings, underground tunnels)
on Mars, the Moon, or the largest asteroids and moons of the system.  The
technology is no more demanding than living under the sea or in orbit and
only somewhat more demanding than living in Antarctica.  The principle
problems would seem to be figuring out (1) how to control a small ecology
successfully, (2) how to acquire most materials you need from local
resources, and (3) how to build and maintain such communities at a price
people on Earth are willing to pay.  (Alternatively you can phrase this
last as "finding jobs on Mars that are so valuable to us on Earth --- i.e.
have such a high wage --- that people can afford and are willing to move to
Mars to live.")
   If Earth-like planets with native lower life exist in other systems, one
could live there perhaps by just bringing along an axe and a mule.  But it
seems likely that if you could eat the life on the other planet it could
eat you, especially the microbial life, and so one might have to expect a
high initial death rate from coming in contact with brand-new diseases.
Christopher Grayce