by Joe Stieber » Sun Jun 21, 2020 8:01 pm
neufer wrote: ↑Sun Jun 21, 2020 12:00 pm
Costello wrote: ↑Sun Jun 21, 2020 6:26 am
Wait a minute : if the Moon [rose]
after the Sun, it means it has already passed the Sun-Earth line...
how could it éclipse the Sun two days later?
The picture is upside down.
The Moon rose slowly... then Venus rose and appeared to overtake & pass behind the Moon.
Technically: the Moon occults Venus.
Actually,
the picture is rotated about 90° clockwise from a direct view (e.g., as seen with binoculars or unaided eyes) at the photographer's location in Estonia when the occultation started around 12:15 pm local summer time (08:18 is stated on his Astrobin page, which must be UT), about 8 hours after the moon, and then Venus, rose a little before 4:30 am local time (they were about 4° apart when rising). The occultation began about 8 hr later, so 4°divided by 8 hr = 0.5°/hr, the well-known nominal rate of the moon's eastward motion against the background sky, which is also about one moon diameter per hour. Since it was close to noon and the objects in question would be near the meridian, the movement of the apparent sky in that area would be essentially horizontal, left-to-right (east-to-west), with the moon moving a bit slower in its inexorable march eastward.
The APOD text is poorly worded, suggesting the moon and Venus rose just after sunrise and "Venus is shown increasingly angularly" close to the moon (whatever that means). Indeed, as Costello indicated, there's a definite inconsistency with the stated rising shortly
after the sun in view of the impending solar eclipse (new moon). I think there was too much of an effort to make today's APOD imitate the "Earthrise" image. This is a fine image in its own right (and would be even better if shown in a correct orientation). Finally, there's no rising or setting of Venus with respect to the moon from our earthly viewpoint as Neufer noted.
[quote=neufer post_id=303373 time=1592740831 user_id=124483]
[quote=Costello post_id=303367 time=1592720784]
Wait a minute : if the Moon [rose] [i]after[/i] the Sun, it means it has already passed the Sun-Earth line...
how could it éclipse the Sun two days later?[/quote]
[b][u][color=#0000FF]The picture is upside down.[/color][/u][/b]
The Moon rose slowly... then Venus rose and appeared to overtake & pass behind the Moon.
Technically: the Moon occults Venus.
[/quote]
Actually, [b][i]the picture is rotated about 90° clockwise from a direct view[/i][/b] (e.g., as seen with binoculars or unaided eyes) at the photographer's location in Estonia when the occultation started around 12:15 pm local summer time (08:18 is stated on his Astrobin page, which must be UT), about 8 hours after the moon, and then Venus, rose a little before 4:30 am local time (they were about 4° apart when rising). The occultation began about 8 hr later, so 4°divided by 8 hr = 0.5°/hr, the well-known nominal rate of the moon's eastward motion against the background sky, which is also about one moon diameter per hour. Since it was close to noon and the objects in question would be near the meridian, the movement of the apparent sky in that area would be essentially horizontal, left-to-right (east-to-west), with the moon moving a bit slower in its inexorable march eastward.
The APOD text is poorly worded, suggesting the moon and Venus rose just after sunrise and "Venus is shown increasingly angularly" close to the moon (whatever that means). Indeed, as Costello indicated, there's a definite inconsistency with the stated rising shortly [i]after[/i] the sun in view of the impending solar eclipse (new moon). I think there was too much of an effort to make today's APOD imitate the "Earthrise" image. This is a fine image in its own right (and would be even better if shown in a correct orientation). Finally, there's no rising or setting of Venus with respect to the moon from our earthly viewpoint as Neufer noted.