APOD: Earth and Moon from Saturn (2013 Jul 22)

Comments and questions about the APOD on the main view screen.
yellowbag

Re: APOD: Earth and Moon from Saturn (2013 Jul 22)

Post by yellowbag » Tue Jul 23, 2013 1:52 am

astonishing. simply astonishing. astounding, phenomonal and flabbergasting!!

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Re: APOD: Earth and Moon from Saturn (2013 Jul 22)

Post by neufer » Tue Jul 23, 2013 2:24 am

RJN wrote:
Today's APOD has been updated due to a better image being released during the day.
So it really is pale blue (without Anthony Barreiro's white shirt being visible that is).
Art Neuendorffer

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Re: APOD: Earth and Moon from Saturn (2013 Jul 22)

Post by Boomer12k » Tue Jul 23, 2013 2:48 am

So....um....well.....er.....uh......Doesn't this make Cassini.... a DRONE?????? :shock: :shock: :shock:

Spying on us....ALL of us....Well it is an interesting picture...and shows that we are all in the same boat....there is no where to go....


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Re: APOD: Earth and Moon from Saturn (2013 Jul 22)

Post by neufer » Tue Jul 23, 2013 2:59 am

Boomer12k wrote:
So....um....well.....er.....uh......Doesn't this make Cassini.... a DRONE?????? :shock: :shock: :shock:

Spying on us....ALL of us....Well it is an interesting picture...
and shows that we are all in the same boat....there is no where to go....
http://www.livescience.com/38340-giant-tuna-capsizes-boat.html wrote: Giant Tuna Capsizes Boat, Pulls Man Into Sea
By Douglas Main, Live Science, July 22, 2013

<<Anthony Wichman had nearly pulled in a massive 230-pound (104 kilograms) Ahi tuna when the fish decided not to give up without a fight, suddenly diving deeper and capsizing Wichman's boat. One problem: The Hawaiian fisherman's leg was wrapped in the line, and he was pulled underwater by the fish, according to news reports. Somehow he managed to free himself and make it back to the boat, where he called his daughter using a waterproof cell phone, according to KHON2, a Hawaiian news station.

"All I could hear was him hyper-ventilating and puking," Anuhea Wichman told KHON2. "And through his breathing, he was able to say three words: sinking, Coast Guard, and buoy." (He had reportedly been fishing near a prominent buoy.) The Coast Guard was then able to find him using the GPS position of his phone.

The fisherman was taken to the hospital with minor injuries, KHON2 reported. Friends of his then hauled his boat back to shore — with the fish still on the line.>>
Art Neuendorffer

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Re: APOD: Earth and Moon from Saturn (2013 Jul 22)

Post by dstn » Tue Jul 23, 2013 3:10 am

Long time APOD fan, first time poster.

Here is my annotated version of the wide-field image version of today's APOD:
http://broiler.astrometry.net/~dstn/temp/17171-ann.jpg

Image

(copy of the original wide-field image is here: http://broiler.astrometry.net/~dstn/temp/17171.jpg -- fun to blink between those two)

Making-of: I took the wide-field image, pulled a few strings and managed to get Astrometry.net to recognize it, then annotated the Henry Draper (HD) stars in the frame. Then I queried the JPL Horizons database to find out where the Earth and Moon would appear (from Saturn, not Cassini, boo); those are the blue and gray dots, for 2013-06-20 to 2013-08-20 in steps of 1 day. (The picture was taken "July 19", according to press.) The grid lines are RA,Dec. Astrometry.net solution: http://nova.astrometry.net/user_images/63212 .

cheers,
dustin

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Re: APOD: Earth and Moon from Saturn (2013 Jul 22)

Post by rj rl » Tue Jul 23, 2013 4:33 am

What's that dusty arc appearing diagonally around the Earth?

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Re: APOD: Earth and Moon from Saturn (2013 Jul 22)

Post by Markus Schwarz » Tue Jul 23, 2013 9:38 am

RJN wrote:Today's APOD has been updated due to a better image being released during the day.
- RJN
This solves my question. Thanks!

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Re: APOD: Earth and Moon from Saturn (2013 Jul 22)

Post by emc » Tue Jul 23, 2013 11:29 am

Chris Peterson wrote:
emc wrote:The image has not been calibrated and I wonder if the horizontal bands are due to interlacing.
The camera doesn't have an interlaced readout. The bands are from noise.
Thanks Chris, I appreciate the information and link.

FARROUT

Re: APOD: Earth and Moon from Saturn (2013 Jul 22)

Post by FARROUT » Tue Jul 23, 2013 12:20 pm

This looks more like the image from Messanger. Did someone make an error?

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Re: APOD: Earth and Moon from Saturn (2013 Jul 22)

Post by dstn » Tue Jul 23, 2013 12:38 pm

No error, this is definitely the one from near Saturn. You can see from the annotation: that it's taken from Saturn; otherwise Earth would appear in front of a different backdrop of stars.

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Re: APOD: Earth and Moon from Saturn (2013 Jul 22)

Post by BMAONE23 » Tue Jul 23, 2013 2:11 pm

neufer wrote:
BMAONE23 wrote:
JamieWalker wrote:
Just curious... What would Jupiter look like at it's closest approach to Saturn?
The moon is 2159 miles diameter and orbits at 238,606 miles distant. It covers an area of the sky equivalent to 0.5 deg (1/2) deg or 30 arc minutes.
At closest approach to Saturn, Jupiter is roughly 100,000,000 miles away. Given it's size of 88846 miles diameter, at that distance it would cover 0.05 deg or 03 arc min. About 1/10th the apparent size of the moon from Earth

My avatar depicts how they would appear relative to the moon as viewed from earth
Roughly 100,000,000 miles away (i.e., ~1.1 AU away)...I don't think so.

Bode's Law states that Saturn & Jupiter should be ~4.8 AU apart and Earth & Jupiter ~4.2 AU apart.

The actual orbits make Saturn & Jupiter ~4.34 AU apart and Earth & Jupiter ~4.2 AU apart.

Hence, Jupiter appears slightly larger from Earth than from Saturn.

Jupiter can be as large as 50.1 arc seconds in Earth's midnight sky with an apparent magnitude of -2.94.

Jupiter can be almost that large in Saturn's midday sky but not nearly so bright.

On June 24, 2000 Jupiter was 4.15 AU away from Saturn at a large 47.5 arc seconds but it was only magnitude 5.2 since only a thin Jupiter South Pole crescent was visible in Saturn's midday sky.

Hence, our view of Jupiter is far superior to Saturn's view.
BMAONE23 wrote:
Nothing worse than Band Noise to disrupt an otherwise harmonious image
http://asterisk.apod.com/viewtopic.php? ... 90#p203608
As usual, Neufer is correct. I should have figured the distance instead of trusting a Google Search. I calculated a relative difference between orbits of 551,070,000 K or 342,419,021 miles but with Jupiter's average orbit of 778,030,000k
But I reach an average distance between Earth and Jupiter of 628,730,000k so Jupiter is closer to Saturn and should appear slightly larger in the sky there than it does here

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Re: APOD: Earth and Moon from Saturn (2013 Jul 22)

Post by rj rl » Tue Jul 23, 2013 2:14 pm

No ideas about this thing http://i.imgur.com/OqGPiRs.jpg?1 ?

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Re: APOD: Earth and Moon from Saturn (2013 Jul 22)

Post by geckzilla » Tue Jul 23, 2013 8:17 pm

rj rl wrote:No ideas about this thing http://i.imgur.com/OqGPiRs.jpg?1 ?
I can't decide if that's some kind of optical artifact from the camera or if it's actually part of the ring system. I know that the previously photographed shadow of Saturn had some similar streaks: http://apod.nasa.gov/apod/ap061016.html
Coincidentally, there are some very similar streaks next to the pale blue dot once again.
Just call me "geck" because "zilla" is like a last name.

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Re: APOD: Earth and Moon from Saturn (2013 Jul 22)

Post by rj rl » Wed Jul 24, 2013 2:14 am

geckzilla wrote:
rj rl wrote:No ideas about this thing http://i.imgur.com/OqGPiRs.jpg?1 ?
I can't decide if that's some kind of optical artifact from the camera or if it's actually part of the ring system. I know that the previously photographed shadow of Saturn had some similar streaks: http://apod.nasa.gov/apod/ap061016.html
Coincidentally, there are some very similar streaks next to the pale blue dot once again.
looks quite similar, the difference being that these streaks are crossing the sun when prolonged, it probably has to do something with optics this time.

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Re: APOD: Earth and Moon from Saturn (2013 Jul 22)

Post by alter-ego » Wed Jul 24, 2013 4:37 am

BMAONE23 wrote:
neufer wrote: Roughly 100,000,000 miles away (i.e., ~1.1 AU away)...I don't think so.

Bode's Law states that Saturn & Jupiter should be ~4.8 AU apart and Earth & Jupiter ~4.2 AU apart.

The actual orbits make Saturn & Jupiter ~4.34 AU apart and Earth & Jupiter ~4.2 AU apart.

Hence, Jupiter appears slightly larger from Earth than from Saturn.

Jupiter can be as large as 50.1 arc seconds in Earth's midnight sky with an apparent magnitude of -2.94.

Jupiter can be almost that large in Saturn's midday sky but not nearly so bright.

On June 24, 2000 Jupiter was 4.15 AU away from Saturn at a large 47.5 arc seconds but it was only magnitude 5.2 since only a thin Jupiter South Pole crescent was visible in Saturn's midday sky.

Hence, our view of Jupiter is far superior to Saturn's view.

As usual, Neufer is correct. I should have figured the distance instead of trusting a Google Search. I calculated a relative difference between orbits of 551,070,000 K or 342,419,021 miles but with Jupiter's average orbit of 778,030,000k
But I reach an average distance between Earth and Jupiter of 628,730,000k so Jupiter is closer to Saturn and should appear slightly larger in the sky there than it does here
Yes you are right, as viewed from Saturn, Jupiter will appear a little larger at closest approach.

The orbit elipticities and orientations lead to a rare close separation (in year 2417) ~3.81 AU, with Jupiter's apparent diameter = 51.8", compared to the a 50.1" maximum apparent diameter from Earth (3.94 AU separation). I identified a time where Jupiter's separation from the Sun (as viewed from Saturn) will be <11 arcminutes, so the view might be pretty neat. I can imagine a dimly lit annulus, and possibly a faint view of the ring(s). Although most of the time I'd prefer viewing Jupiter from Earth, Jupiter at or near inferior conjunction might yield some nice photos.

Of course, I'm thinking we would be outside of Saturn's atmosphere.
A pessimist is nothing more than an experienced optimist

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Re: APOD: Earth and Moon from Saturn (2013 Jul 22)

Post by Psnarf » Wed Jul 24, 2013 1:24 pm

That's me waving, third row, second from the left.

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Re: APOD: Earth and Moon from Saturn (2013 Jul 22)

Post by neufer » Wed Jul 24, 2013 1:49 pm

alter-ego wrote: Yes you are right, as viewed from Saturn, Jupiter will appear a little larger at closest approach.

The orbit ellipticities and orientations lead to a rare close separation (in year 2417) ~3.81 AU, with Jupiter's apparent diameter = 51.8", compared to the a 50.1" maximum apparent diameter from Earth (3.94 AU separation). I identified a time where Jupiter's separation from the Sun (as viewed from Saturn) will be <11 arcminutes, so the view might be pretty neat. I can imagine a dimly lit annulus, and possibly a faint view of the ring(s). Although most of the time I'd prefer viewing Jupiter from Earth, Jupiter at or near inferior conjunction might yield some nice photos.

Of course, I'm thinking we would be outside of Saturn's atmosphere.
The rare Jupiter transit would be nice.
(Jupiter being a tenth the size of the Sun but 2.2 times closer to Saturn making it ~22% the apparent size.)
Art Neuendorffer

casus

Re: APOD: Earth and Moon from Saturn (2013 Jul 22)

Post by casus » Thu Jul 25, 2013 1:23 pm

why did no one mention that the light from earth/moon took an hour and 20 minutes to reach the camera? (according to my calcs...)

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Re: APOD: Earth and Moon from Saturn (2013 Jul 22)

Post by neufer » Thu Jul 25, 2013 1:34 pm

Psnarf wrote:
That's me waving, third row, second from the left.
From your avatar one would have thought you to be more camera shy.
Art Neuendorffer