Earth's intrinsic glow.

["Kevin 'Tex' Houston" <hous0042@maroon.tc.umn.edu>]

Kelly Starks x7066 MS 10-39 wrote:
> 
> At 10:21 AM 7/19/96, Kevin 'Tex' Houston wrote:
> >I wonder what such a probe would reveal about earth?  Assuming a .4 C
> >fly-by and a
> >favorable position (ie earth is seen from a distance equal to 60 to 120
> >degrees of
> >earth's orbit.) would a standard set of spectrographic instruments be able
> >to detect
> >Oxygen or Carbon Dioxide?  Would a wide band radio reciever be able to
> >detect our
> >television or satellite transmissions?  Would a good night-side photo show the
> >rivers and seas of light that populate the north-american continet?
> >
> >In other words, if some other world sent a probe here,what is the minimum
> >sensitivity
> >required for it to return useful data? (ie. that the third rock from the
> >sun is a
> >life-bearing world)  Follow-up question, do we have the required technology?
> >
> >--
> >Kevin "Tex" Houston    http://umn.edu/~hous0042/index.html
> 
> I know we don't show up that well in the day visually.  But with a big
> enough scope you can resolve down to any res you want.  We have designs
> (well concepts) that could resolve objects down to a couple meters from a
> few light years away.  The geometric structures of our roads, fields, and

Okay, but could you do it on the fly (at .4C) and keep it small enough to 
be an easy sale to the politicians (you've seen how horrendously expensive
interstellar flight can be.) and could you have a wide enough field of vision
to detecty something you didn't know was there to start with


> agraculture would be a dead give away.  The geometric pattern of city
> street lights, and trafic flows, at night would be an incredibly obvious
> hint!!

So what's the smallest cammera you could get away with to spot this from 
1 AU away?

> 
> In the radio and EM bands we are VERY bright.  We outshine the sun in some
> EM bands.  Personally as an ET I'ld be a little suspicious of a planet

But that's only because the sun doesn't shine in those bands. how far away is 
our power grid visible?  I'd think spillage from a sattelite uplink would be
more visible than leakage from a power grid over light years, if only due to 
there being a tighter beam from the up-link.

> where whole continents were syncronized with a 60 cycle per secound hum
> (I.E. our power grid).  I have no idea what the transmition rating for the
> power grid is, but I'm sure you could detect it a few light years away.

I don't know about that, you might be able to chalk it up to some strange rock
formation that's re-radiating sunlight with some kind of storage ability to 
account for nighttime transmissions.  Kind of like glow-in the dark minerals
that can stay lit for hours after the light is out.

> 
> The question isn't could they see us, but how closely would they be
> looking.  We have no official programs looking, and few private ones.  Then
> again, we'ld be pretty hard to overlook at close range!
> 

The real question is "how big a system do we need to spot non-intelligent life
in a system we know nothing about at a decent fraction of the speed of light."

-- 
Kevin "Tex" Houston 	http://umn.edu/~hous0042/index.html

Every time a third party candidate comes up, both major parties say:
"You can't vote for him, you'll just be handing the election to the other guy"
Well, Democrat and Republican are just two different names for the same thief, 
So what does it really matter?  This time I'm voting Libertarian.
Harry Browne for President.  http://www.HarryBrowne96.org/   (800) 682-1776