Moon Geological Period & Jupiter Belts

Date: 15 & 16th June 08, Sunday & Monday
Observation Time: 11:30pm to 1am (1:30 hr) on both days
Location: SD Home, CA
Weather: Seeing was excellent. Because of moon light, whole sky was washed out.

Highlight of the Night: Moon geological period and Jupiter disk.

Phase of the moon: 2 days before full moon. Waxing gibbous with 96% of the Moon's visible disk illuminated.

Watched moon on both sun & mon. Mainly at 194x, with 12mm 2x barlow.

Followed the terminator from SW corner to NW. Crater Schikard, Fourier, humorium basin, Eddington basin and Crater Pythagoras.

The main thing I focused on is to get the angular judgment of the size and distance of these craters compared other prominent feature. e.g. It was fun to measure distances between Crater Kepler to Enke, which was ~4deg.. and Kepler-Mauris around ~12 deg. Again these distances are just rough estimation, but it was fun to get the judgment correct.

Another thing i focused on is to understand the geological time scale of these features. E.g crater Tycho being in Copernitian period, while crater Phtyagoras is in Eratosthenes period... means tycho being much younger than pythagoras, which must be younger than nearby crater babbage which must be younger than crater archimedese or crater plato. This estimation of age was fun to track.

Watched Jupiter on both sun/mon. On sunday, Just watched it for 5 mins and clouds rolled over. On monday spent more than 20mins. Overall, I saw jupiter with really good clarity. On sunday, Calisto was transitioning on Jupiter at the NE edge..

Most of the observations of Jupiter were at 194x, with 12mm 2x barlow. I used blue, green and red filter on it. The blue and green filters were indeed helpful. I also tried the moon filter on jupiter.. it indeed reduced the brightness of jupiter disk.. but din't help anything more than that.

North equatorial belt south equatorial belt were clearly visible. northen belt seems to be darker than southern one, but southern one is surely wider than nourthen one. Also, with some effort, I saw N & S polar regions as well. also, I saw the north tropical zone gap. I felt its existence because that area is like a strip which is brigher/white than the north eq belt.

It must be fun to watch Jupiter without moonlight.. also at 250x and above. Lack of high magnification eyepiece indeed made me sad :) !!

Any way, it was first time, I watched Jupiter so seriously and with such a clarity.. It was indeed a good learning experience on how you can train your eyes to see a object.