by MarkBour » Wed Mar 20, 2019 7:38 pm
neufer wrote: ↑Mon Mar 18, 2019 8:57 am
Now lets have sent those
Ultima-Thule star occultation teams to the dark skies of Paranal and La Silla to measure the temporal eclipse brightness variation for a moon location that passes through the center of the Umbra from 3:19UT to 5:19UT (with perhaps a nearby patch of dark sky as a control).
Those teams should observe an temporal asymmetry in that patch of moon brightness around the revised 4:19UT (= 1:19AM Chile) eclipse time due in small (though measurable) part to the sunset shadowing of Mauna Kea (prior to eclipse).
So, I'm a happy little photon who just left the Sun, headed toward the Moon. At the time of my travel, the Earth is coming into my path and rotating so that Mauna Kea is just turning into the "sunset edge" of Earth, perfectly so that Mauna Kea sticks out at its very maximum profile elongation, right as I come zipping by. Now if Mauna Kea gets in my way, I'm toast, and I cannot illuminate the Moon. But if it weren't there, and I just miss planet Earth, going through the atmosphere at a minimum altitude of 2 km above the gentle Pacific ocean, will I get to the Moon? According to alter-ego, a finding is that most every photon that gets that low into Earth's atmosphere is not going to get through. I think even from the ISS it would be very difficult to see the contour of a mountain on the edge of the Earth. As an effect that merely increases the darkness of the edge nicely timed at an ISS-sunset or ISS-sunrise, it probably would require some rather sensitive equipment focused in on the region. Any such effect would be very diffuse because of all of the scattering.
[quote=neufer post_id=290677 time=1552899464 user_id=124483]
Now lets have sent those [url=https://en.wikipedia.org/wiki/(486958)_2014_MU69#2017_occultations]Ultima-Thule star occultation teams[/url] to the dark skies of Paranal and La Silla to measure the temporal eclipse brightness variation for a moon location that passes through the center of the Umbra from 3:19UT to 5:19UT (with perhaps a nearby patch of dark sky as a control).
Those teams should observe an temporal asymmetry in that patch of moon brightness around the revised 4:19UT (= 1:19AM Chile) eclipse time due in small (though measurable) part to the sunset shadowing of Mauna Kea (prior to eclipse).
[/quote]
So, I'm a happy little photon who just left the Sun, headed toward the Moon. At the time of my travel, the Earth is coming into my path and rotating so that Mauna Kea is just turning into the "sunset edge" of Earth, perfectly so that Mauna Kea sticks out at its very maximum profile elongation, right as I come zipping by. Now if Mauna Kea gets in my way, I'm toast, and I cannot illuminate the Moon. But if it weren't there, and I just miss planet Earth, going through the atmosphere at a minimum altitude of 2 km above the gentle Pacific ocean, will I get to the Moon? According to alter-ego, a finding is that most every photon that gets that low into Earth's atmosphere is not going to get through. I think even from the ISS it would be very difficult to see the contour of a mountain on the edge of the Earth. As an effect that merely increases the darkness of the edge nicely timed at an ISS-sunset or ISS-sunrise, it probably would require some rather sensitive equipment focused in on the region. Any such effect would be very diffuse because of all of the scattering.