Re: which side of the moon recieves more light over a year?

"Richard Tobin" <richard@xxxxxxxxxxxxxxx> wrote in message
news:ecuas7$2nq9$1@xxxxxxxxxxxxxxxxxxxxxxxxxx
In article <Xns982C9C02AFE5Dtaylorntaylorblancha@xxxxxxxxxxxxxx>,
Taylor blanchard <taylor@xxxxxxxxxxxxxxxxxxxx> wrote:

1) The direct sunlight is never interupted (during the lunar day) on the
far side but is eclipsed by the earth once or twice a year on the near
side. Therefore, the far side of the moon actually receives a few MORE
hours of direct sunlight per year.

2) Earthlight falls almost constantly (in varying amounts as the earth
goes through it's phases) onto the nearside in the same way that
moonlight falls onto earth but earthlight never falls onto the far side.
Therefore the far side receives LESS (none at all) sunlight reflected
off the earth.

When the near side of the moon is facing the sun, it's on the side of
the earth further from the sun. When the far side is facing the sun,
it's on the side of the earth nearer to the sun. So on average the
far side is nearer to the sun when it receives direct sunlight, by
up to about half a million miles.

-- Richard

Indeed. So the net amount of radiation received is about 1/4% more (inverse
square law) on the far side for this reason alone. However, if the question
was reworded slightly to ask which side of the Moon gets hotter, I think it
would be the near side, because it has a lower albedo and absorbs much more
of the sunlight. There are only some very small dark patches on the more
reflective far side, while all the maria are on the near side.

The blockage of light by eclipses is much less over a year than the 1/4%
mentioned above, though this factor would increase the amount by which the
far side gets more sunlight.

The main effect of Earth on the heating of the Moon is probably from
infrared radiation, not optical reflection, but still tiny compared to the
net difference due to distance from the Sun for the two sides when
illuminated (factor of order 10^5).

--
Mike Dworetsky

(Remove "pants" spamblock to send e-mail)

.

Relevant Pages

  • Why be a believer?
    ... > SECOND the Universe is incomprehensible in size and by comparison our World ... > Sun, Stars and Planets revolved around the Earth. ... > Acoran [Supreme] ...
    (alt.religion.christian)
  • Re: Why do the Sun, and Moon, appear to be the same size from earth?
    ... The distance from the Earth to the Moon is 108 times the diameter of ... you can fit 108 moons between the Earth and the Moon – ... and the Sun. ... the distance from the Earth to the Sun is ~107.4697 diameters of the ...
    (rec.music.classical.guitar)
  • Re: QuestionEvolution.com News
    ... Here's the Solar System page from the site, ... After several thousand eccentric orbits around the sun, ... gets captured by Saturn, and there's another moon. ... I suspect the Earth and the Sun started of pretty much the same, ...
    (talk.origins)
  • Re: need arbitration about a physics problem
    ... | The author claimed that you when stand on Jupiter's moon Io, ... | gravitational field due to Jupiter alone: ... significantly farther from the Sun than Earth is, ...
    (sci.physics)
  • Re: The Heavenly Match: A Cosmic Oddity
    ... occurrence on earth - at least once a year somewhere on the globe. ... Where the ratio of the sun to moon size is ... It's just a coincidence. ... each with a random number of moons and moon sizes. ...
    (talk.origins)
Loading