Simulation of April 21, 2014 Event

[bigmasterdrago]

I have been unable to simulate this image taken by Hubble of the shadow of Ganymede transiting the GRS.
What do I need to do different than normal settings?

https://www.dailymail.co.uk/sciencetech/...-here.html

[PMSchu]

Whoever wrote the DM article keeps referring to 'Saturn' in parts of the article. It's clearly Jupiter.

Phil S.

[theskyhound]

I found it on 2014 April 21 20:00 UT.

   

Now, you might say that its not perfect. But, for goodness sake that's really close! I'm pretty proud of that one. Consider:

1. The GRS is a cloud formation that drifts about with respect to the cloud formations in the band around it.

2. The cloud formations in the band drift over time as well and they are difficult to pin down over long periods of time. 

3. We can only track either of the above based on amateur observations that are difficult to make without a clear point of reference

4. Every other commercial software that I know of simply uses the current location of the GRS (e.g. today) and it would likely put the GRS on the other side of the planet

When I set up SkyTools to predict the position of the historical position GRS, I didn't have such a well-defined example to go on. I mean, exactly when does the GRS cross the center meridian? Everyone is just eyeballing it. With this observation I should be able to nail it down much closer.

[PMSchu]

That's pretty good for 8 years of accumulated drift of the GRS which has a mind of its own, apparently. Way better that the author of the DM article who can't keep Saturn & Jupiter straight. Maybe it's the caption writer, not the author.

Phil S.

[bigmasterdrago]

Thanks Skyhound. I had run through the full day and a half and could not for some reason get any alignment. Works for me now. Thanks again. Not sure what I was doing wrong. How far from present day will the position of the GRS be fairly accurate?

---

And Phil, the DM article is referring to Saturn at least a few times. But it does trip the reader up by switching back and forth.
https://www.cnet.com/science/nasa-releas...en-before/

[theskyhound]

Its difficult to say how far into the future the GRS position will be accurate. I did implement an extrapolation function that is pretty smart, but the GRS has a tendency to jump sudden in position from time to time, and that would eventually throw it off. Other than something like that, it should be highly accurate for a least a year, and pretty accurate for maybe 5.

[bigmasterdrago]

You should see how far off some of the other software I have used over the years tried to simulate this event.

[PMSchu]

Hi BMD,

Check out the Daily Mail article's little sidebar titled "Jupiter's Six-Sided Storm". The first sentence reads," A bizarre six-sided storm churning Saturn’s north pole has flummoxed astronomers ever since it was first spotted thirty years ago." Looks like they could use some fact-checkers, actually proof-readers. That's pretty bad - totally wrong. The actual article is correct, but the caption writer got it wrong. Very confusing.

They have some nice pictures though. Jupiter looks spectacular, as always.

Phil S.

[bigmasterdrago]

I have it on good authority that the science writers at the DM don't understand the subject matter are transposing information from other sources, and making a complete mess of it!