Re: Sunrise on Clavius

On Feb 26, 9:10 am, "John Carruthers" <joncarruth...@xxxxxxxxxxx>
wrote:
On 26 Feb, 13:28, "William C. Keel" <k...@xxxxxxxxxxxxxxxxxx> wrote:

My 14-year-old son and I saw some spectacle last night. The fact that
the sunlight yet touched only the center of the crater floor was
a graphic illustration of how strongly curved the luanr surface is.

Well done. Your son will never forget this observation and you
won't either.
Tonite's a good night to count the craters on the floor of Clavius.

Well observed Bill, I had a similar demonstration at our last clear
public night. What I initially took to be a star about to be occulted
by the moon was in fact a central peak standing a hair off the
northern limb ;-) I watched fascinated as it slowly dipped from view.
jc
I call those crater tops "floaters". They are more fun to
observe
than the craters themselves - really wierd looking.
They can also be very useful in determining altitudes if one
wants
to do some hardball Trigonometry.

Ben, 90.126 n 35.539

.