Hey Chuck It's 2:08AM here in Hawaii and I'm about ready to haul it to the top of Haleakala for the morning grouping. Coffee is made, car is packed and from what I see, summit wind is 1.37 mph, humidity 7.4% and IR cloud cam shows very little if any high cirrus. See ya, Rob

Chuck and Joe I added 2 photos from this morning. Venus appeared at first as a great orange star, followed by a thin crescent moon that got lost in the blaze as the sun rose. I had to coax Saturn w/ some contrast enhancement to make it visible in the photo. Haleakala is such a GREAT place to watch the rising sun and to encounter the night sky. A hui ho Rob

Aloha Joe I'll shoot the ZL next month when it REALLY shines and then submit photos to S+T. In the tropics the ZL is more common through out the year, we see it maybe 6 months out of the year, but late September and late April are tops. The ZL looks like a sword piercing the night sky, very impressive. Aloha Rob

This one was especially beautiful because of the observatory. Thanks again, Joe

Jeez, it looks like you've taken purdy pitchers before!

ah, just a few ............. ;^)

Hi Kurt It was a tough shot, didn't see Saturn till I put the files up on the screen, but I sure like being at the summit!! aloha Rob

--- Rob Ratkowski Photography <ratkwski@hawaii.rr.com> wrote:

It was a tough shot, . . .

P.S. - I'd take a 4 deg x 6 deg blow up (the Moon is 1/2 deg for measuring) showing the planets and the Moon and ship it off to APOD. - Kurt __________________________________________________ Do You Yahoo!? Tired of spam? Yahoo! Mail has the best spam protection around http://mail.yahoo.com

--- Chuck Hards <chuckhards@yahoo.com> wrote:

...

From here the skyglow was too bright for a photo, by the time the moon cleared the mountains.

The height of the Wasatsch Mtn.s and some clouds blocked it out in SLC. For this one, you really needed to get some altitude (like Rob did) so you can look down or at least level and across the dark horizon. - Kurt __________________________________________________ Do You Yahoo!? Tired of spam? Yahoo! Mail has the best spam protection around http://mail.yahoo.com

--- Chuck Hards <chuckhards@yahoo.com> wrote:

The moon a planetary body? Is there another planetary . . . Sorry Kurt, I couldn't resist! ;o)

Okay, a solar system body that's still bigger than three or four IAU planets.

BTW, the earthshine this AM was especially strong...I wonder what the earth's cloud-cover percentage was at the time, on the daylight hemisphere?

Earthshine on the Moon is the strongest just before and after new Moon (on the 23rd) - and not just because of the Moon's low illuminated fraction. The reason for this is the Moon is inclined in its orbit at about 6 degs from the Earth's equator. At new Moon and full Moon, the Moon moves crosses the ecliptic plane. Thus, relatively more sunlight reflected off the Earth directly hits the Moon. As we approach the equinoxes, Earthshine also increases because the Earth is crossing the ecliptic at the same time. My own preference is for Earthshine just before the new Moon in the early morning just after the autumnal equinox and just before the spring equinox. Earthshine has the most steely-blue color to it during it's early morning risings. But this occurs each month in the mornings before new Moon. The general public are more familiar with Earthshine a day or so after new Moon, when the Moon is rising in the west after sunset. Most people are awake then and they are more likely to see it. - Kurt __________________________________________________ Do You Yahoo!? Tired of spam? Yahoo! Mail has the best spam protection around http://mail.yahoo.com

--- Chuck Hards <chuckhards@yahoo.com> wrote:

I know all that of course, but it still seemed brighter than an ecliptic alignment would account for - thus my pondering cloud cover.

Sorry for the misread. Don't know, but I don't feel a global cloud cover is a factor in the overall intensity of Earthshine. I feel it has more to do with the background brightness of the sky bringing out a better contrast and the relative Moon-Earth distance. Twilight is longer in the summer = less favorable contrast. The relative Moon-Earth distance for Earthshine is the inverse of the extraordinarily bright full Moon effect. But my RASC Observer's Handbook and MICA ephemeris is showing the Moon around 401,000 km distant on the 21st. That's closer to apogee than perigee. - Kurt __________________________________________________ Do You Yahoo!? Tired of spam? Yahoo! Mail has the best spam protection around http://mail.yahoo.com

--- Chuck Hards <chuckhards@yahoo.com> wrote:

I'm moving on.

See ya.

Considering the relative albedos of a mostly cloudless vs. cloud-covered hemisphere, I'd be willing to bet that at extremes it still has a greater effect on earthshine than distance.

It was a sufficiently cool question that I checked out the journal literature. Here are my notes and links for group archival purposes: Apparently, the relationship between Earthshine and the Earth's albedo wasn't looked at closely until recently as part of the study of global climate change. In 2003, a researcher at the CIT and Big Bear Solar Observatory developed an automated CCD camera system to measure the albedo of the Earth using Earthshine reflected off the Moon as a detector. Effectively Goode was using the Moon as a photographic big "grey" card. He mathematically compensated for changes in Earthshine from the phase and position of Moon and lunar topography - leaving only the Earth's albedo. Variations in Earthshine are well-correlated with the Earth's albedo. It looks like within a single year, variations in the Earth's albedo are around -+8%.

From 1985 to 2003, there was an annual average variation of +8% to -2%.

Goode used "daily cloud-cover data from Intellicast" to come up with an estimate of the daily global cloud cover. Goode, P. et al. 2003. Sunshine, Earthshine and Climate Change II. http://adsabs.harvard.edu/cgi-bin/nph-bib_query?bibcode=2003JKAS...36S..83G Per Figure 2 - +-8% (within a single year) Earthshine project public ed. science info summary http://www.bbso.njit.edu/science_may28.html http://www.bbso.njit.edu/espr/sci_images/fig_watts_website.gif (annual variations - 1985-2003 - +10% to -2%) http://www.bbso.njit.edu/espr/sci_images/trycover3.jpg Big Bear Solar Observatory - Earthshine project http://www.bbso.njit.edu/Research/EarthShine/ http://www.bbso.njit.edu/ Palle, E. et al. 2003. Earthshine and the Earth's albedo 2. http://adsabs.harvard.edu/cgi-bin/nph-bib_query?bibcode=2003JGRD.108vACL13P Thejll, P., Goode, P. 2002. Earthshine: A Proposal to Build an Automatic System for Observing Terrestrial Albedo. (abstract). http://adsabs.harvard.edu/cgi-bin/nph-bib_query?bibcode=2002EGSGA..27.4058T Qui, J. Goode, P. 2003. Earthshine and the Earth's albedo: 1. http://adsabs.harvard.edu/cgi-bin/nph-bib_query?bibcode=2003JGRD.108vACL12Q Koonin, S.E. 1998. Earthshine and the Earth's Albedo. http://www.bbso.njit.edu/Research/EarthShine/espaper/earthshine_paper.html __________________________________________________ Do You Yahoo!? Tired of spam? Yahoo! Mail has the best spam protection around http://mail.yahoo.com