Monday, April 09, 2007

Blue sky, naked eye moon

On my way to work this morning, saw Moon nearly the same elevation as the roof tops of the southerly buildings lining 6th Ave. A beautiful clear, cerulean blue sky as a canvas. With foreground objects that included the tree twigs and the buildings, Moon looked larger than usual.

I noticed two brighter, grayish marks central to the waning gibbous. I stopped pulled out a piece of paper and srew a schematic of the features I could detect naked eye. The most noticeable were the two features just mentioned: Copernicus & Kepler; Aristarchus could be seen just above Kepler. Further along the top a brightening thick line partially crossed the disk. I suspected this to separate Mare Frigoris from Mare Imbrium.

The moon's western limb was brighter than the rest of the visible lunar disk and Grimaldi appeared to be nestled in the border around an 8:00 position. In towards the "center of the clock" from Grimaldi, two separate maria are discernible: Mare Nubium on the terminator side (east) and Mare Humorum was the western one. They appeared nearly equal in size. Above them the large, darkened floor of Oceanum Procellarum seemed to occupy most, but not all of the gibbous Moon. I suspected a thin whitish line encroaching from the east towards Copernicus. May have possibly seen the Apennines mountain range.

Crossing the street, Moon looked to be nearly centered over the avenue, that is manhattan-due-south . But Manhattan is rotated 30° so checked Planetarium for the Palm revealing its altitude/azimuth at 14°04'/208°43'.

Labels: ,