HomeLatest ThreadsGreatest ThreadsForums & GroupsMy SubscriptionsMy Posts
DU Home » Latest Threads » Forums & Groups » Topics » Science » Science (Group) » Fascinating collection of...

Mon Sep 7, 2020, 01:10 PM

Fascinating collection of photos taken during Cassini's final orbits around Saturn (Video)

A video posted this past June on the channel “Astrum” is an utterly fascinating collection of shots taken by Cassini as well as graphics of its orbital path (edit; As well as animations, which add to the story). An example of some of the really interesting stuff is that a “Shepherd Moon” - Daphnis - is actually captured within the plane of the rings and disrupts the rings on either side of it, like a boat makes a wake. I had absolutely no idea! Well, it isn’t a surprise that I had no idea, as I am not quite the student of our Solar System that I would like to think I am!!

I don’t think I have ever put up a post in this group, so forgive me if this has been posted before. I searched for a post containing this video but couldn’t find one.

Anyway, take ten minutes and be amazed;




Edit to add that this video does have an advertisement for a VPN at the end.

13 replies, 988 views

Reply to this thread

Back to top Alert abuse

Always highlight: 10 newest replies | Replies posted after I mark a forum
Replies to this discussion thread
Arrow 13 replies Author Time Post
Reply Fascinating collection of photos taken during Cassini's final orbits around Saturn (Video) (Original post)
A HERETIC I AM Sep 2020 OP
brer cat Sep 2020 #1
A HERETIC I AM Sep 2020 #2
yonder Sep 2020 #3
A HERETIC I AM Sep 2020 #5
yonder Sep 2020 #7
A HERETIC I AM Sep 2020 #8
yonder Sep 2020 #9
A HERETIC I AM Sep 2020 #10
myccrider Sep 2020 #11
yonder Sep 2020 #12
myccrider Sep 2020 #13
Jeebo Sep 2020 #4
A HERETIC I AM Sep 2020 #6

Response to A HERETIC I AM (Original post)

Mon Sep 7, 2020, 01:46 PM

1. Thank you for the post.

That was fascinating.

Reply to this post

Back to top Alert abuse Link here Permalink


Response to brer cat (Reply #1)

Mon Sep 7, 2020, 01:47 PM

2. Glad you enjoyed it!

Reply to this post

Back to top Alert abuse Link here Permalink


Response to A HERETIC I AM (Original post)

Mon Sep 7, 2020, 02:09 PM

3. I stumbled across this two nights ago. Watched it again just now, thanks.

Interesting that in the final plunge they chose to send more data rather than photos to maximize bandwidth value. Scientists doing what scientists do, thankfully.

Reply to this post

Back to top Alert abuse Link here Permalink


Response to yonder (Reply #3)

Mon Sep 7, 2020, 04:12 PM

5. I found that interesting as well.

The trade off on how to best use the bandwidth, yes?

It is simply beyond remarkable what these talented men and women are capable of.

Orbital calculations that are essentially threading a needle from a million miles away, so to speak.

I once read something to the effect that the accuracy of the math needed to insert a Mars bound spacecraft into Martian orbit was the equivalent of shooting a basket located in the Staples Center in LA from the top of the Empire State Building and hitting nothing but net.

This sort of thing is another level entirely.


Reply to this post

Back to top Alert abuse Link here Permalink


Response to A HERETIC I AM (Reply #5)

Mon Sep 7, 2020, 04:49 PM

7. Yes, absolutely another level. Reminds me of surveyor jokes the boss might press you with:

"You're staking out some curb, not building a Steinway. Get a move on!"

OR

"You're calculating your traverse closure, not a trajectory to Mars. Hustle it up!"

Reply to this post

Back to top Alert abuse Link here Permalink


Response to yonder (Reply #7)

Mon Sep 7, 2020, 05:11 PM

8. LOL!

My brother and I have put a Few things together in the past and the “well, we ain’t building a piano” comment has come up more than once!

Yes indeed.

It would seem to me that the variance of the calculation down to the 4th decimal (or more, perhaps) means either getting it through the rings of Saturn or sending the craft completely elsewhere!

Reply to this post

Back to top Alert abuse Link here Permalink


Response to A HERETIC I AM (Reply #8)

Mon Sep 7, 2020, 05:25 PM

9. And to think that in the 60's some of that stuff was done with slide rules.

I'm not sure I could still work one - add or multiply would be about it, if anything.

It's no wonder why we see those clips of scientists and engineers in a control room jumping up for joy when a certain aspect of a mission has been confirmed a success. A wing and a prayer comes to mind for me but they would probably say: "nah, all science."

Reply to this post

Back to top Alert abuse Link here Permalink


Response to yonder (Reply #9)

Mon Sep 7, 2020, 05:48 PM

10. Absolutely!

I put up this thread originally back in 2009, on the 40th anniversary of the Apollo 11 landing, and then again last year. I said basically the same thing;

https://www.democraticunderground.com/100212285887

To think that the most commonly used calculation tool in those days was a slide rule and that the entire program, down to the smallest rivet, was done before the days of CAD/CAM assisted tooling and machining, is just mind blowing

Reply to this post

Back to top Alert abuse Link here Permalink


Response to yonder (Reply #9)

Tue Sep 8, 2020, 12:26 AM

11. IKR?

I’m not sure I could even add or multiply with a slide rule anymore!

My husband designed some parts for the cabins in the Apollo missions and he did it with a slide rule (he’s almost 10 years older). I never used one at a job because calculators became so ubiquitous.

The 1st time I took college trig/pre-calc in ‘69 they had a rule that you could NOT bring a calculator to class. I had to quit in my sophomore year and didn’t get back for over 5 years. I took trig again, same college, as a refresher but the rules had changed such that a calculator was REQUIRED!?!

Eventually could afford an HP 15C in the mid-80s. Still have that baby and it still works like a charm.

Reply to this post

Back to top Alert abuse Link here Permalink


Response to myccrider (Reply #11)

Tue Sep 8, 2020, 02:25 AM

12. HP's eh? God's gift to humanity if you ask me.

I have an 11c, two 15c's, a couple of 32s II's, a 33s I think, a 48gx with surveying cards, a 45s and used to have a brand new 42s which I traded for one of the 15c's thirty years ago. That was a mistake but now have a 42 emulator on my phone which has accepted an old star/sun shot program that works just fine. Now that I'm semi-retired, most of them just collect dust in the drawer.

Of all of them, the beater 15c was the work horse. It went into the field with me every day, had half a dozen simple surveying programs in it (what, some 250-300 program lines of memory total??), you could bang it around and was easily worth its weight in gold. Those were days when almost all calculations were done in the field with very little office support other than a plat or a set of plans and maybe some record coordinates. And the batteries! I'm willing to bet you can't remember the last time you replaced those button batteries in yours, myccrider. Am I right? They last forever, like 5-10 years of everyday, hard use, probably 12 or more unused.

And RPN. Enough said other than once you get onto it, it's tough to go back. Hell, it's downright painful when forced to use a common cruncher.

So I'll hop off the HP soapbox and apologize to the OP for busting the thread. I'll just maintain the blame is shared for you bringing up your own HP15c, which is a much, much better tool than a slide rule and a moldering book of sine tables.



Reply to this post

Back to top Alert abuse Link here Permalink


Response to yonder (Reply #12)

Sat Sep 19, 2020, 07:28 PM

13. Reverse Polish FTW!

Yep, haven’t changed the battery for over 10 years. I was just thinking the other day that I should get a spare, just in case.

Reply to this post

Back to top Alert abuse Link here Permalink


Response to A HERETIC I AM (Original post)

Mon Sep 7, 2020, 02:41 PM

4. The Cassini mission was amazing.

They posted lots of pictures from Cassini on the Astronomy Picture of the Day site, and they were all just simply breathtaking. Thank you for posting this.

-- Ron

Reply to this post

Back to top Alert abuse Link here Permalink


Response to Jeebo (Reply #4)

Mon Sep 7, 2020, 04:13 PM

6. You are welcome!

I searched “Cassini” on DU and found numerous threads over the years, so there is clearly interest.

I’m glad you enjoyed the video

Reply to this post

Back to top Alert abuse Link here Permalink

Reply to this thread