Weak Interstellar Messages Pass us
bY
SOME
SUGGESTED FREQUENCIES
Since the atmosphere is
fairly transparent to 860.2649 Mhz (which is half of 1720.5299
Mhz, the highest emmission frequency of OH, and the top part of
the "water hole" ) and the others listed below, we're
using an off-of-the-shelf Radio Shack desk-top scanner (which is
frequency limited by the FCC/Gov't; we can't get the frequencies
listed below in black, without making illegal modifications) to
listen to the following candidate frequencies (approximately, because our scanner
does'nt have good frequency resolution!) colored in red:
|
Initial Freq. Mhz.
|
init.freq. /2
|
init.freq. /3
|
init.freq. /4
|
init.freq. /5
|
init.freq. /6
|
init.freq. /7
|
init.freq. /8
|
init.freq. /9
|
init.freq. /10
|
init.freq. /11
|
init.freq. /12
|
H |
1420.4057 |
710.202 |
473.4685 |
355.1014 |
284.0811 |
236.7342 |
202.9151 |
177.5507 |
157.8228 |
142.0405 |
129.1277 |
118.3671 |
OH |
1720.5299 |
860.2649 |
573.5099 |
430.1324 |
344.1059 |
286.7549 |
245.7899 |
215.0662 |
191.1699 |
172.0529 |
156.4118 |
143.3774 |
OH |
1667.3590 |
833.6795 |
555.7863 |
416.8397 |
333.4718 |
277.8931 |
238.1941 |
208.4197 |
185.2621 |
166.7359 |
151.5780 |
138.9465 |
OH |
1665.4018 |
832.7009 |
555.1339 |
416.3504 |
333.0803 |
277.5669 |
237.9145 |
208.1752 |
185.0446 |
166.5401 |
151.4001 |
138.7834 |
OH |
1612.2310 |
806.1155 |
537.4103 |
403.0577 |
322.4462 |
268.7051 |
230.3187 |
201.5288 |
179.1367 |
161.2231 |
146.5664 |
134.3525 |
D(H2) |
327.384 |
163.692 |
109.128 |
81.846 |
65.4768 |
54.564 |
46.7691 |
40.923 |
36.376 |
32.7384 |
29.762 |
27.282 |
Deuterium (D) or (H2
) , is an isotope of hydrogen with twice its mass. Hydrogen is
the most prevalent element in the universe, so I'm listening to
frequencies related to Deuterium, even though it isn't in the
"waterhole". Before I started this project, I checked
some reference sources (including my cousin, a HAM radio
operator) who feel that the atmosphere is relatively transparent
above 60 Mhz, which was great news to me because I had a
misconception that, from Earth, microwave SETI was the best
window on the radio universe. Below 60 Mhz atmospheric deflection
is problematic and may not be fruitful for a ground based radio
SETI (although I'll tune in anyway in case non-deflected signals
get through or ETI's find a way around the deflection problem by
using near Earth transmissions or some other means.)
Once in awhile I actually
do this project (but rarely these days), and I also listen to
frequencies within 300 kilohertz (as suggested by Giuseppe
Cocconi and Phillip Morrison in their article [Nature, Sept. 19,
1959]) of the frequencies listed above (in red) to compensate for
the effect of transmitters and receivers on moving planets in our
region of the galaxy (I'm making the obvious assumption that the
transmitting planet is not far, in cosmic terms, because of our
weak reception capablilities).
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W.I.M.P.Y.