Custer weekly chronicle. [volume] (Custer City, S.D.) 1890-1931, 1891-08-01
LUNAR TEMPERATURE.
It IL Not Much Below 100 n. I'm One
Writer'S Opinion.

Mr. Peal Is under the impression
that have omitted TO take into ac-
count the question OF the temperature
OF the moon. says writer In the En-
giish Mechanic. 1t Is true that / did
not consider 1t requisite to raise dis.
cussion on that question. but had
satisfied myself by collecting ali tho
evidcrce obtainable. that the tempera-
ture of tho moon was considerably
above the freezing point, and l made
my calculations for that point accord
ingly. In doing so | considered that
/ was giving rather than receiving an
| advantage.
i will now state my reasons for re-
jecting all The extravagaHt assump-
lions of the existence Of an excessive
| ly low temperature on the moon. rs
| well rs the extreme estimates Of the
temperature of space. think that we
| have evidence 10 show from our own
experience OF the long night in our
own polar regions very much longer
than the lunar mighty that the tenn
/ perature OF space cannot be lower
| than 100 degrees below Fahrenheit's 5
/ zero, or about 73 degrees G. below the
/ freezing point. Tho lowest recorded
temperature OF the polar regions cam
( not be many degrees above the tenn
! perature of space. or above that OF the
| coolest region of tho moon. because
| the effect of an atmosphere Is merely
/ TO retard or delay radiation by few
/ days or hours, not TO prevent 1t alto
| gethor.
/ Mr. Peal arrives at his estimate of q
possible lunar temperature OF 800 de-
grees below zero by process that Is
/ altogether inadmissible. He assumes
that the radiation from the moon is
excessively great, and that the heating
power of the sun Is excessively small.
That is an impossibiity, the two con-
| ditions being irreconcilable. We know
from our terrestrial experience that the
good radiators of heat are good alb
sorbers of heat. aud that bad absorb
ers are bad radiators. Mr.. Peal may
! take his choice OF the ways Of looking
at this matter. but he cannot be al
| lowed to take half OF one aud half OF
; the other to make good his theory. II
the want Of an atmospheric jacket pro-
notes radiation, it must also promote
absorption, and II the dark side OF the
moon is excessively cold, the illumi-
mated side must be excessively hot; or.
conversely. II the suns rays do not
bring the moons surface 10 high
temperature, the radiation cannot low
er Il much. 1t does not matter what
his choice may be; in either case the
conclusion must be against his as.
sumption.
A provisional estimate of the tenn
perature Of the moon may be arrived
at by taking mean of the actual OBJ
servations, which range from 80 to 500
degrees. say 266 degrees for the illumi-
mated equatorial region of the moon,
and assuming that the temperature oi
the dark side falls as low as 100 de.
grees below zero. This gives an
average of 50 degrees which. strange
| TO say, Is about the same as the
average temperature OF the earth's
equator. The temperature of the lunar
poles may also be taken as about the
same as that of our own Polar regions.
There is no reason why this estimate
should not be accepted as approximate
ly correct. The real influence OF an
atmosphere is to retard for time the
manifestation of extremes OF tempera-
ture, whether hot or cold-not 10 in
crease the average. The mean tenn
perature of the moon should therefore,
be about the same as that If the earth