On Friday, April 14, 2017 at 11:10:37 PM UTC+1, Mike Collins wrote:
Gerald Kelleher wrote:
On Friday, April 14, 2017 at 2:20:27 PM UTC+1, Mike Collins wrote:
Gerald Kelleher wrote:
On Thursday, April 13, 2017 at 9:38:32 PM UTC+1, palsing wrote:
http://www.youtube.com/watch_popup?v=dE-vOscpiNc

What a wonderful story and the event where the Earth comes into view seen
from an orbiting spacecraft.

Of course the image is diminished by present company who insist on a
dynamical absurdity as people looking out at the moon that day would have
seen the half phase of the moon or thereabouts.

When people feel at home with imaging and using it for interpretation
then they can consider themselves to be among astronomers.


Wrong!
There was a waxing moon with 29% illumination. It's easy to see this since
you merely have to look at the Earth. The moon from Earth will have the
opposite phase the the Earth from the moon.
Your inability to visualise this is the reason you get things so wrong..

Suit yourself, thereabouts at the time of the images means less than two
days from half phase -

https://www.calendar-12.com/moon_calendar/1968/december

The original image ,outside the spectacular first observation that it
was, should have generated so much additional material for working as
with it subsequent orbit of the spacecraft and 'earthrise' the change in
the circle of illumination could be noted along with the changing
relationship between the Earth's polar points and the circle of illumination.

The classrooms of schools and colleges became the intellectual killing
fields and extermination camps for astronomical interpretation and the
relationship between planetary dynamics and terrestrial sciences but
that era is slowly passing away and a new era is dawning. Given the Holy
Day that is in it, there is that strange darkness at the South Pole that
signals a wonderful period ahead -

https://www.usap.gov/videoclipsandmaps/spwebcam.cfm






Look at your own link. It's described as a waxing crescent moon. Nobody
would look at this and say it was almost a half moon.
Scientifically the image was of no significance. But it was a public
relations triumph (like the Apollo 8 mission itself). I had a poster of
this on the wall above the fireplace of my flat for years.

In the dreary empirical world all imaging has no significance but it is not so with genuine astronomy and astronomers and there is a paradise of imaging out there presently.

The orbiting spacecraft covers lunar terrain not seen from Earth and visa versa hence 'earthrise' is a property of the orbiting spacecraft and not the moon which doesn't rotate. All the insightful nuggets of information such as the Earth appears fully illuminated as seen from the moon while the moon appears completely dark as the side that always faces us turns away from the Sun while a few weeks later the opposite is the case. Of course this is an Earth centered perspective.The Sun centered perspective is different in the matter of planetary dynamics in that the Earth turns in two distinct ways to the central Sun hence the observed changes in the relationship between the polar points and the circle of illumination over time.

Like musical composition it is delightful to play around with imaging and create an narrative that others may enjoy. The dull and the sour don't allow their spiritual side to break through their pretenses, intellectual or otherwise, and miss out on this adventurous endeavor.