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.|
Image © Roger Powell
I’m one of the founder members of Macarthur Astronomical Society and current webmaster.