Saturn

It’s currently a good time for planets. In the Western early evening sky, Venus is rising and Mars is still very slowly sinking – and in the Eastern late evening, Saturn is rising, with Jupiter and Neptune close behind. I took this video at 11.45 pm, when it was about 23° above the horizon. Look closely and you can see the shadow of Saturn on the rings.

Did you know that Saturn appears in our sky thirteen days later each year?

While its sidereal period (its year) lasts for 29.46 Earth years, its synodic period is 1.035 Earth years (378.1 Earth days). Each Earth year Saturn has travelled a little further around its orbit and it takes Earth a year and 13 days to catch up again.

In contrast, the synodic period of Mars is a whopping 780 Earth days, which goes some way to explaining why it is lingering for so long in our Western sky after conjunction last October.

1000 frame video.
Date: 17th June 2021
Stacked in Autostakkert using the best 10% of frames.

Thanks for reading 🙃


Telescope & Imaging Details

Telescope:SkyWatcher Esprit 120 mm apochromatic 3-element refractor; 840 mm f/l @ f/7.
Optics:Field flattener; no filter.
Mount & Guiding:SkyWatcher EQ6-R Pro mount; ZWO ASI120 guide camera.
Imaging camera: ZWO ASI 290 uncooled.
Software:Control: Cartes du Ciel, ASCOM, EQMOD, PHD2. Imaging: SharpCap, Autostakkert, Gimp.
Observatory:34° South.

Image © Roger Powell

I’m one of the founder members of Macarthur Astronomical Society and current webmaster.

8 Comments

  1. What a nice view of Saturn. I got used to seeing it and Jupiter in the pre-dawn twilight as I am an early riser. I need to start watching the late evening sky. My front window faces east. Your diagram and explanation were perfect.

    Liked by 1 person

    1. I have rarely viewed the morning sky since retiring. So it’s evenings only for me and it’s nice to see Venus in one direction, with Saturn and Jupiter later on in the opposite direction, like welcoming old friends back.

      Liked by 1 person

  2. Nice shot! I think I’m going to wait a little longer until they come out earlier at night 🙂 I am curious though from where you are what the maximum altitude Saturn and Jupiter attain. Here at 34 degrees north latitude they don’t get above 30, at least this year. That makes it really tough to get good video unless the seeing is phenomenal.
    Dave

    Like

    1. This was taken with Saturn at 23º altitude from 34ºS but if I’d stayed around until Saturn crossed the meridian at 3.15 am, it would have reached a peak of 73º 31′.

      This would be higher than you would observe currently due to Saturn being in that part of the ecliptic which is South of the celestial equator. However, it surprises me that the planet only reaches 30º altitude at 34º N – but in a few years time the opposite will occur.

      I might have a second go at it in August when it is at opposition and ever so slightly closer and bigger.

      Liked by 2 people

  3. Excellent image. I always love seeing the shadows on the rings. Something about the fact that the same light source making shadows on Earth, is that powerful to make shadows still so far away.

    And such a polite planet, Saturn is, allowing only a year and 13 days for us to catch up. Unlike those hasty planets, like Jupiter. Or Mars. And let’s not even get started on Venus and Mercury.

    Liked by 1 person

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