archive: RE: [ASTRO] Re: SETI in radio

RE: [ASTRO] Re: SETI in radio

Larry Klaes ( )
Wed, 9 Sep 1998 13:26:38 -0400

Greg, I agree with you on many of your points regarding SETI,
life in the solar system/galaxy/Universe, and so forth, but my
main question to you is then: How else do you expect us to
ever find out if alien life, intelligent or otherwise, exists beyond
Earth if we do not conduct some kind of search/expedition?

If I said that I hope ETI come landing on Earth with their big
interstellar spaceships and ask us to join the Galactic Club,
I would expect derision from this group at best. While it may
not be impossible, I for one do not forsee this happening any
time soon, if ever. There are too many stars in the Milky Way
galaxy (400 billion) and the distances are too far between them
for me to expect Earth and humanity to be on any ETI's popularity
list. And certainly ETI may be designed such that they do not
use technology or even consider looking for beings on other worlds.

These numbers in stellar quantity and distance also make it very
difficult for humanity to find out if there is life in other star systems.
NASA can't even decide when or if to send astronauts to Mars in the
next twenty years, so I don't think interstellar probes will be happening
in my lifetime, either (but somebody please prove me wrong here).

The only other alternative we have at present to finding ETI is to
search for their optical (laser, infrared) and microwave (radio, radar)
signals, either because the ETI are aiming them deliberately at us to
get our attention, or if we happen to get hit by their transmissions by
chance while they are sending them elsewhere.

I grant you this sounds like wishful thinking, but at least it is plausible
both technically and scientifically, and the best we can do at present,
given my reasons above.

If you know of some other way to look for ETI which does not require
our going to every star system in person, I would like to know it.

As for looking in our solar system, that at least is obtainable in the
near future. Here too I do not know if we will be successful in finding
actual microbes or the fossils of such former creatures on Mars and
Europa, nor do I immediately expect there are "mysterious" beings
on those spheres as well, but once again, we need to explore these
worlds far more thoroughly than we have so far to be certain. And
we should explore them anyway to study them as fascinating worlds
in their own right.


From: Greg Crinklaw
Sent: Tuesday, September 08, 1998 7:19 PM
Subject: Re: [ASTRO] Re: SETI in radio

Larry Klaes wrote:
> ----------
> From: Greg Crinklaw
> Sent: Saturday, September 05, 1998 8:05 PM
> Subject: Re: [ASTRO] Re: SETI in radio
> ...
> We've been looking for life in the solar system for over 30 years now.
> What have we found? Nada. That's a fact, not an emotional statement.
> This isn't to say that life does not exist elsewhere, but it is saying
> something rather profound--at the very best, life in our solar system
> outside of the earth is small and well hidden. The qustion os no
> longer one of if the solar system is barren, but just how barren it
> is.
> Greg
> Other than depositing two immobile Viking landers on Mars in 1976,
> which scraped a few inches of Martian soil, what else have we done
> to deliberately search for life in the Sol system? Granted we found
> no life - present or past - in the lunar regolith returned to Earth, but
> neither did we expect any.
> And while planetary probes have shown that neighboring worlds are far
> less likely to contain life than we once thought before they went there,
> we have literally only scratched the surface (and atmosphere) of most
> of the worlds in our system. Think about how much we don't know of
> Neptune, for example, even though Voyager 2 did return a lot of new
> data in 1989. One flyby of a planet is not enough. Imagine an alien
> probe making one flyby of Earth.

I would have to imagine a very limited probe for it not to find strong
evidence for the presence of life on earth, even in a single flyby.
It's this sort of fuzzy logic that I'm speaking about! The argument
that the solar system is teeming with mysterious life forms that we've
missed because we haven't looked hard enough just doesn't stand up to
scrutiny. One only has to consider the chemical evidence. The presence
of all but the most tenuous life form will be revealed by its effect
on the chemistry of the atmosphere of the planet. It doesn't matter
what kind of life you presume--there must be some chemical process at
work. Just compare the earth to Venus--this is no small effect! Life
on earth has profoundly altered the chemistry of the atmosphere,
making it chemically unique in very significant ways. You have to
really stretch yourself into the realm of science fiction to come up
with prodigious life forms on other planets that have not altered
their environments as well.

I'm really surprised this is a contentious issue. It seems to me that
anyone who even took a cursory look at the chemistry of the
atmospheres of the planets would find this obvious.


-- Greg Crinklawcrinklaw@totacc.comAstronomical Software DeveloperAstronomy EducatorCapellaSoft:, New Mexico