2 August 2006

Observing Location	Staten Island Ferry, New York Harbor I rode the ferry a few times tonight to get into some moving air. It was only hot (~90°F) and humid moving air so really wasn’t much help. On the first trip over to SI I noticed the Moon and on a return trip I went to the upper outside deck to see if any stars were also visible. The ferry is not an ideal platform for observing. There are big flood lights aimed down at the deck to make it safe for passengers to walk around and they are so close that it is hard to block them out with an upraised hand. And the ferry doesn’t go in a straight line so the star you are trying to look at is continually moving around in your field of view while you are trying to maintain your balance as the boat rocks a bit on the wakes of other vessels.
Observational Period	2130-2200 EDT
Atmospheric Conditions	Hazy, hot and humid Transparency Good Seeing
Instruments	Naked-eye Observing - Charlie
Observing Party	Charlie Ridgway

Naked-eye Limiting Magnitude

I was out without Planetarium again so had to do it all from memory. North East Zenith West South Object Mag Spica α Vir 0.98 Arcturus α Boo -0.05 Alkaid η UMa 1.85 Mizar ζ UMa 2.23 Alioth ε UMa 1.76 Phad γ UMa 2.41 Merak β UMA 2.34 Dubhe α UMA 1.81 Polaris α UMi 1.97 Kochab β UMi 2.07 Pherkad γ UMi 3.00 Vega α Lyr 0.03 Deneb &aphya; Cyg 1.25 Sadr γ Cyg 2.23 δ Cyg 2.86 31 Cyg 3.80 32 Cyg 3.96 Gienah Cygni ε Cyg 2.48 Alberio 2.9 Altair α Aql 0.76 Tarazed γ Aql 2.72 Deneb el Okab ζ Cyg 2.99 δ Aql 3.36

Target	Moon
Constellation	Lib
Category	Lunar
Time	060802.2130 EDT
Comments	I could see the moon out over Staten Island before we left the dock in Manhattan. It was slightly gibbous. I could see mare on the sunlit side but couldn’t really make out any features. Seeing the arc of the terminator there and wondering how far past First Quarter it was got me to thinking about a discussion Peter and I had about how long a lunation was and I decided to do some checking on that in Planetarium. 1st Quarter Full Moon Last Quarter New Moon 3Jul06 8d0h31m 10Jul06 15d10h57m 17Julo6 22d3h7m 25Jul05 29d12h25m 2Aug06 8d4h15m 9Aug06 15d6h23m 15Aug06 21d21h20m 23Aug06 29d14h38m 31Aug06 8d3h47m 7Sep06 14d23h32m 14Sep06 21d16h6m 22Sep06 29d16h35m To get the age of the New Moon I looked it up in Planetarium which said its age was 0h0d0m so I backed the time off by one minute to get the length of each lunation. So it appears that the length of a lunation is not a constant. Will this have any affect on how easy it is to see opposing crescent Moons? That got me to wondering if the fact that the length of the lunations I was observing were constantly increasing were a coincidence or part of a pattern. The explanation I came up with was that it would take longer for the Moon to go around the Earth when it was farther away. But it gets close and far on each lunation so that probably doesn't hold.