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APOD: Planet Parade over Sydney Opera House (2022 Apr 26)

Posted: Tue Apr 26, 2022 4:06 am
by APOD Robot
Image Planet Parade over Sydney Opera House

Explanation: The world is waking up to a picturesque planet parade. Just before dawn, the eastern skies over much of planet Earth are decorated by a notable line of familiar planets. In much of Earth's northern hemisphere, this line of planets appears most nearly horizontal, but in much of Earth's southern hemisphere, the line appears more nearly vertical. Pictured over the Sydney Opera House in southern Australia, the planet line was captured nearly vertical about five days ago. From top to bottom, the morning planets are Saturn, Mars, Venus, and Jupiter. As April ends, the angular distance between Venus and Jupiter will gradually pass below a degree as they switch places. Then, as May ends, Jupiter will pass near Mars as those two planets switch places. In June, the parade will briefly expand to include Mercury.

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Re: APOD: Planet Parade over Sydney Opera House (2022 Apr 26)

Posted: Tue Apr 26, 2022 11:47 am
by orin stepanek
PlanetParadeSydney_Agrawal_960.jpg
From top to Opera house; Saturn; Mars; Venus; Jupiter!
Earth the bottom planet :D Very nicely done!
https://ak.picdn.net/shutterstock/video ... humb/1.jpg
Url of dog & cat!

Re: APOD: Planet Parade over Sydney Opera House (2022 Apr 26)

Posted: Tue Apr 26, 2022 5:06 pm
by MoonRockMan
Why exactly is the line of planets mostly horizontal in the northern hemisphere but more vertical in the southern hemisphere? :)

Re: APOD: Planet Parade over Sydney Opera House (2022 Apr 26)

Posted: Tue Apr 26, 2022 6:27 pm
by bystander
MoonRockMan wrote: Tue Apr 26, 2022 5:06 pm Why exactly is the line of planets mostly horizontal in the northern hemisphere but more vertical in the southern hemisphere? :)

I wondered that myself, but I think it has to do with the difference between the Earth's equatorial plane and the ecliptic, the Earth's path around the Sun. (I say the ecliptic, but it's more likely the plane of the Solar system.)

Re: APOD: Planet Parade over Sydney Opera House (2022 Apr 26)

Posted: Tue Apr 26, 2022 7:06 pm
by Chris Peterson
MoonRockMan wrote: Tue Apr 26, 2022 5:06 pm Why exactly is the line of planets mostly horizontal in the northern hemisphere but more vertical in the southern hemisphere? :)
The ecliptic sweeps across the sky over the course of the day. In Sydney, a bit before dawn, it passed almost straight overhead, so we see the planets vertical with respect to the eastern horizon. In New York the ecliptic is overhead now in the middle of the day, and the planets look vertical with respect to the western horizon. But since the Sun is up, we don't see them. The planets would be horizontal in Sydney in late morning.

Re: APOD: Planet Parade over Sydney Opera House (2022 Apr 26)

Posted: Tue Apr 26, 2022 7:23 pm
by MoonRockMan
bystander wrote: Tue Apr 26, 2022 6:27 pm
MoonRockMan wrote: Tue Apr 26, 2022 5:06 pm Why exactly is the line of planets mostly horizontal in the northern hemisphere but more vertical in the southern hemisphere? :)

I wondered that myself, but I think it has to do with the difference between the Earth's equatorial plane and the ecliptic, the Earth's path around the Sun. (I say the ecliptic, but it's more likely the plane of the Solar system.)
Chris Peterson wrote: Tue Apr 26, 2022 7:06 pm The ecliptic sweeps across the sky over the course of the day. In Sydney, a bit before dawn, it passed almost straight overhead, so we see the planets vertical with respect to the eastern horizon. In New York the ecliptic is overhead now in the middle of the day, and the planets look vertical with respect to the western horizon. But since the Sun is up, we don't see them. The planets would be horizontal in Sydney in late morning.
Thank you so much!