by VictorBorun » Mon Sep 06, 2021 4:42 pm
neufer wrote: ↑Mon Sep 06, 2021 3:58 pm
VictorBorun wrote: ↑Mon Sep 06, 2021 2:39 pm
Just imagine that thing, 7.3 times bigger than the moon in vizual size, 53 times larger in visual area and 100 times greater in albedo*area, sitting still in zenith all the time and changing only its phase from full Charon at midnight to half Charon at sunrise or sunset to a thin sickle at noon.
- Near equinox Charon goes through a full monthly phase.
However, around the solstices Charon never gets closer to the Sun than ~60° or further than ~120°.
https://en.wikipedia.org/wiki/Pluto#Rotation wrote:
<<Pluto's rotation period, its day, is equal to 6.387 Earth days. Like Uranus, Pluto rotates on its "side" in its orbital plane, with an axial tilt of 120°, and so its seasonal variation is extreme; at its solstices, one-fourth of its surface is in continuous daylight, whereas another fourth is in continuous darkness. (Note: Charon has an inclination of 0.08° to Pluto's equator)>>
So my picture for a realty disadvertisment under Charon was correct only for equinoxes.
On the winter solstice even at noon Charon's crescent is (1−Sin60°)R thick which is 67‰ of Charon's diameter rather than zero.
On the summer solstice even at midnight Charon's gibbous is (1+Sin60°)R thin which is 933‰ of Charon's diameter rather than 1000.
[quote=neufer post_id=316445 time=1630943885 user_id=124483]
[quote=VictorBorun post_id=316442 time=1630939184 user_id=145500]
Just imagine that thing, 7.3 times bigger than the moon in vizual size, 53 times larger in visual area and 100 times greater in albedo*area, sitting still in zenith all the time and changing only its phase from full Charon at midnight to half Charon at sunrise or sunset to a thin sickle at noon.[/quote]
[list][b][u]Near equinox[/u][/b] Charon goes through a full monthly phase.[/list]
However, around the solstices Charon never gets closer to the Sun than ~60° or further than ~120°.
[quote=https://en.wikipedia.org/wiki/Pluto#Rotation]
<<Pluto's rotation period, its day, is equal to 6.387 Earth days. Like Uranus, Pluto rotates on its "side" in its orbital plane, with an axial tilt of 120°, and so its seasonal variation is extreme; at its solstices, one-fourth of its surface is in continuous daylight, whereas another fourth is in continuous darkness. (Note: Charon has an inclination of 0.08° to Pluto's equator)>>[/quote]
[/quote]
So my picture for a realty disadvertisment under Charon was correct only for equinoxes.
On the winter solstice even at noon Charon's crescent is (1−Sin60°)R thick which is 67‰ of Charon's diameter rather than zero.
On the summer solstice even at midnight Charon's gibbous is (1+Sin60°)R thin which is 933‰ of Charon's diameter rather than 1000.