by MarkBour » Fri Aug 19, 2022 11:20 pm
rstevenson wrote: ↑Fri Aug 19, 2022 7:46 pm
Thanks Mark. I assumed, because I didn’t know better, that the Saturn images were taken as close to one year apart as possible. No doubt there’s software that can help with planning (or explaining) this sort of thing.
Rob
Maybe some that's especially good for it. I certainly like good old Stellarium. Their online version at:
https://stellarium-web.org/
is super-easy to use.
I did try setting it to August 19, and Saturn was nicely visible this evening.
As I changed the year counter backwards, by one-year increments, at first it looked like Saturn would easily be captured every year on August 19 from my porch. However, as I got back past about 2013, I had to catch him earlier and earlier in the evening, and around 2010, it became impossible. He was too close to the Sun from Earth's sky on that date. I couldn't see him looking like he'd be able to be caught in the dark again on August 19 until about 2005 or so and then in the morning, but then was easily available for a number of years going further back. So, that's what happens on August 19. After looking at this a while, I think that when it happens, it doesn't matter where on the Earth you are, it's just Saturn in conjunction with Sol, from anywhere on Earth.
I'm pretty sure that if you picked another date, you'd have the same thing happen once in the 30-year cycle, it would just be different years for different dates on Earth's calendar. I wonder, then, how much you'd have to adjust. Maybe if you take the picture every year + about 12 days, you'll have consistent results. So, we could take a shot tonight, then on August 31, 2023, then September 12, 2024, etc. If you go for this approach, of course, in 30 years you'll only get 29 images.
[quote=rstevenson post_id=325219 time=1660938393 user_id=124801]
Thanks Mark. I assumed, because I didn’t know better, that the Saturn images were taken as close to one year apart as possible. No doubt there’s software that can help with planning (or explaining) this sort of thing.
Rob
[/quote]
Maybe some that's especially good for it. I certainly like good old Stellarium. Their online version at:
[url]https://stellarium-web.org/[/url]
is super-easy to use.
I did try setting it to August 19, and Saturn was nicely visible this evening.
As I changed the year counter backwards, by one-year increments, at first it looked like Saturn would easily be captured every year on August 19 from my porch. However, as I got back past about 2013, I had to catch him earlier and earlier in the evening, and around 2010, it became impossible. He was too close to the Sun from Earth's sky on that date. I couldn't see him looking like he'd be able to be caught in the dark again on August 19 until about 2005 or so and then in the morning, but then was easily available for a number of years going further back. So, that's what happens on August 19. After looking at this a while, I think that when it happens, it doesn't matter where on the Earth you are, it's just Saturn in conjunction with Sol, from anywhere on Earth.
I'm pretty sure that if you picked another date, you'd have the same thing happen once in the 30-year cycle, it would just be different years for different dates on Earth's calendar. I wonder, then, how much you'd have to adjust. Maybe if you take the picture every year + about 12 days, you'll have consistent results. So, we could take a shot tonight, then on August 31, 2023, then September 12, 2024, etc. If you go for this approach, of course, in 30 years you'll only get 29 images.