[AZ-Observing] Morning Observing, July 29
- From: Tom Polakis <tpolakis@xxxxxxx>
- To: <AZ-Observing@xxxxxxxxxxxxx>
- Date: Fri, 29 Jul 2005 11:25:32 -0400
This morning, Jenn and I rose at 3:30 to have a look at Mars and the moon, just
past Third Quarter. The temperature was all the way down to 85F, and a light
easterly breeze was a sign that seeing would not be great.
Mars has reached a diameter of 11", so 280x brings its apparent diameter
through the eyepiece up to nearly 1 degree. The planet is currently about "as
gibbous as it gets", with the illumination at 84 percent. Along the full
length of the limb was a brighter limb haze, which shows up in many webcam
images. Near the meridian was Mare Sirenum, which I find to be the least
interesting of the aspects of Mars, unless you're hunting for Olympus Mons.
We'll try that when the planet approaches opposition.
The moon was at a very favorable phase. The sun was setting on Tycho, and only
the tip of its central peak was illuminated, looking like a faint star. More
impressive was the sunset lighting on Rupes Recta, the Straight Wall. A shadow
cast by the crater Birt and the rise surrounding it broke the Straight Wall
into two segments. Here's a good image of the approaching shadow before it
reaches the wall. Our view was at a much lower sun angle.
http://www.lpod.org/archive/2004/02/LPOD-2004-02-22.htm
As twilight was coming up, all of Orion minus Rigel was visible. Orion in July?
Tom
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