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APOD: Two Views of Earth (2013 Jul 23)

Posted: Tue Jul 23, 2013 4:15 am
by APOD Robot
Image Two Views of Earth

Explanation: In a cross-Solar System interplanetary first, our Earth was photographed during the same day from both Mercury and Saturn. Pictured on the left, Earth is the pale blue dot just below the rings of Saturn, as captured by the robotic Cassini spacecraft now orbiting the gas giant. Pictured on the right, the Earth-Moon system is seen against a dark background, as captured by the robotic MESSENGER spacecraft now orbiting Mercury. In the MESSENGER image, the Earth (left) and Moon (right) shine brightly with reflected sunlight. MESSENGER took the overexposed image last Friday as part of a search for small natural satellites of the innermost planet, moons that would be expected to be quite dim. During this same day, humans across planet Earth snapped many of their own pictures of Saturn.

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Re: APOD: Two Views of Earth (2013 Jul 23)

Posted: Tue Jul 23, 2013 4:29 am
by bystander

Re: APOD: Two Views of Earth (2013 Jul 23)

Posted: Tue Jul 23, 2013 4:43 am
by Boomer12k
Yeah, that's the one from Mercury....gee...they get you coming and going.... :D

Nice Rings!

:---[===] *

Re: APOD: Two Views of Earth (2013 Jul 23)

Posted: Tue Jul 23, 2013 5:42 am
by Ann
http://asterisk.apod.com/viewtopic.php?p=203614#p203614

In the post that I have provided a link to, Earth looks downright yellow. How can that be?

These are a few of my theories:

1) The Earth isn't the same color "all over". In this picture, the yellow deserts of Africa and Saudi Arabia show off prominently. Perhaps the Earth turned its yellowest side to Cassini as it was being photographed?

2) The CCD cameras of Cassini might be more sensitive to red than to blue light. Perhaps the Cassini images need to be "adjusted" somewhat before they show the "true color" of an object, and maybe someone rushed ahead and posted the picture of the Earth before it had been adjusted to a "natural" color?

3) Surely the Earth hasn't become yellower since it was first photographed as a "pale blue dot"???? :shock:

4) The picture of the Earth from Cassini got its color from this guy?

Ann

Re: APOD: Two Views of Earth (2013 Jul 23)

Posted: Tue Jul 23, 2013 5:57 am
by Justin
would love to see this same diptych without the big white arrow ruining the photo!!!! I can see where earth is quite clearly on my own thanks heh =D

Re: APOD: Two Views of Earth (2013 Jul 23)

Posted: Tue Jul 23, 2013 5:59 am
by Justin
I decided to look instead of just complaining lol http://photojournal.jpl.nasa.gov/jpegMo ... modest.jpg !

Re: APOD: Two Views of Earth (2013 Jul 23)

Posted: Tue Jul 23, 2013 6:44 am
by geckzilla
Justin wrote:I decided to look instead of just complaining lol http://photojournal.jpl.nasa.gov/jpegMo ... modest.jpg !
A larger one is available too. http://photojournal.jpl.nasa.gov/catalog/PIA17038

Re: APOD: Two Views of Earth (2013 Jul 23)

Posted: Tue Jul 23, 2013 8:45 am
by owlice
Ann wrote:In the post that I have provided a link to, Earth looks downright yellow. How can that be?

These are a few of my theories:

1) The Earth isn't the same color "all over". In this picture, the yellow deserts of Africa and Saudi Arabia show off prominently. Perhaps the Earth turned its yellowest side to Cassini as it was being photographed?
No. http://asterisk.apod.com/viewtopic.php? ... 12#p203515
Ann wrote:2) The CCD cameras of Cassini might be more sensitive to red than to blue light. Perhaps the Cassini images need to be "adjusted" somewhat before they show the "true color" of an object, and maybe someone rushed ahead and posted the picture of the Earth before it had been adjusted to a "natural" color?
The image was identified as a raw image; it showed an overexposed Earth. There was no rushing ahead, unless you prefer not to be shown images as they become available. Go look again, and you'll see that the image on APOD was updated when a processed image became available (as mentioned on the thread devoted to that image/APOD).

~~~~~~~~~~~~~~~~~~~~~~~~

I think today's APOD is a stunning image! How little Earth is, from wherever it's viewed!

Re: APOD: Two Views of Earth (2013 Jul 23)

Posted: Tue Jul 23, 2013 9:05 am
by fisherman
would someone identify the blue band of light across the picture in the Saturn photo thankyou

Re: APOD: Two Views of Earth (2013 Jul 23)

Posted: Tue Jul 23, 2013 9:22 am
by Ann
fisherman wrote:would someone identify the blue band of light across the picture in the Saturn photo thankyou
My guess is that this might possibly be the E ring, made of ice particles ejected by active moon Enceladus. These tiny ice particles create a broad, diffuse ring aroung Saturn. The E ring is also blue in color, which seems to fit what we are seeing here.

Ann

Re: APOD: Two Views of Earth (2013 Jul 23)

Posted: Tue Jul 23, 2013 9:57 am
by Rob Bar
".....as captured by the robotic Cassini spacecraft now the gas giant." Should be near ???

Re: APOD: Two Views of Earth (2013 Jul 23)

Posted: Tue Jul 23, 2013 10:54 am
by neufer
You can do cross-eyed stereoscopy to observe the Earth & Moon in 3D.

Re: APOD: Two Views of Earth (2013 Jul 23)

Posted: Tue Jul 23, 2013 11:41 am
by emc
The Saturn image is an awesome composition. I love the perspective of the space traveler.

Re: APOD: Two Views of Earth (2013 Jul 23)

Posted: Tue Jul 23, 2013 11:54 am
by dstn
Maybe it's rude to double-post, but this is actually about today's APOD, not yesterday's: An annotated version of the Cassini shot!

Image

Details at old post http://asterisk.apod.com/viewtopic.php? ... 61#p203756

cheers,
dustin

Re: APOD: Two Views of Earth (2013 Jul 23)

Posted: Tue Jul 23, 2013 12:35 pm
by dstn
And here's the annotated version of the Messenger shot:
http://broiler.astrometry.net/~dstn/temp/ann-mess.jpg

Image

I was surprised this worked, since the stars are pretty faint, but bringing up the brightness/contrast helped me see them (the code had no problem with the original!). This is a wider-field image, so there are too many Henry Draper stars to label. Again, the Earth and Moon as seen from Mercury are shown with the blue and gray dots, respectively. I plotted the whole period 2013-06-20 through 2013-08-20 on a 1-day period (though clearly most of that period is out of the frame). Grid lines are RA,Dec.

Here's the Astrometry.net solution: http://nova.astrometry.net/user_images/63236

cheers,
dustin

Re: APOD: Two Views of Earth (2013 Jul 23)

Posted: Tue Jul 23, 2013 12:38 pm
by emc
dstn wrote:Maybe it's rude to double-post, but this is actually about today's APOD, not yesterday's: An annotated version of the Cassini shot!

Image

Details at old post http://asterisk.apod.com/viewtopic.php? ... 61#p203756

cheers,
dustin
I appreciate the Earth and Moon trails. Now I can better imagine that I'm there watching home fly distantly by!

Re: APOD: Two Views of Earth (2013 Jul 23)

Posted: Tue Jul 23, 2013 12:49 pm
by emc
neufer wrote:You can do cross-eyed stereoscopy to observe the Earth & Moon in 3D.
I tried the 3D outer space stereo super scope viewing and now understand the comic cosmic commodious concept of two directions at once!
Image

Re: APOD: Two Views of Earth (2013 Jul 23)

Posted: Tue Jul 23, 2013 12:59 pm
by dstn
emc wrote:I appreciate the Earth and Moon trails. Now I can better imagine that I'm there watching home fly distantly by!
I like that you can see the orbit of the Moon over the two-month period; it also gives you an idea of how far apart Earth and the Moon *could* have looked.

--dstn

Re: APOD: Two Views of Earth (2013 Jul 23)

Posted: Tue Jul 23, 2013 12:59 pm
by neufer
APOD Robot wrote:Image Two Views of Earth

In the MESSENGER image, the Earth (left) and Moon (right) shine brightly with reflected sunlight.
MESSENGER's simulated view of Pluto & New Horizons.

Re: APOD: Two Views of Earth (2013 Jul 23)

Posted: Tue Jul 23, 2013 1:10 pm
by OzRattler
Congratulations on this photo. It puts "us" into perspective without doubt and is a major reason why this is my favourite site to visit daily.

I am also impressed that : " robotic Cassini spacecraft now the gas giant."

Humans are most clever at being able to replace Saturn with our own probe. ;)

Take care and keeping enjoying the views,

OzRattler.

...insanity is so confusing...

Re: APOD: Two Views of Earth (2013 Jul 23)

Posted: Tue Jul 23, 2013 1:21 pm
by FloridaMike
neufer wrote:You can do cross-eyed stereoscopy to observe the Earth & Moon in 3D.
:lol2:

Re: APOD: Two Views of Earth (2013 Jul 23)

Posted: Tue Jul 23, 2013 1:39 pm
by DragonHeart335
First time posting...todays APOD is wonderful. Very cool to see Earth with its moon from Messenger! Thanks!

Re: APOD: Two Views of Earth (2013 Jul 23)

Posted: Tue Jul 23, 2013 1:49 pm
by Beyond
emc wrote:
neufer wrote:You can do cross-eyed stereoscopy to observe the Earth & Moon in 3D.
I tried the 3D outer space stereo super scope viewing and now understand the comic cosmic commodious concept of two directions at once!
Image
:yes:

Re: APOD: Two Views of Earth (2013 Jul 23)

Posted: Tue Jul 23, 2013 2:56 pm
by K1NS
We all know the old meme about why they climbed Mt. Everest. "Because it is there."

Well, taking photos of Earth from Saturn and Mercury serve absolutely no purpose. But they took the photos because they were there. And purposeless or not, it is absolutely thrilling to see those photos. They're better than the view from the top of Mt. Everest, yeah? Makes one proud to live on that little dot.

Re: APOD: Two Views of Earth (2013 Jul 23)

Posted: Tue Jul 23, 2013 3:23 pm
by geckzilla
Ann wrote:
fisherman wrote:would someone identify the blue band of light across the picture in the Saturn photo thankyou
My guess is that this might possibly be the E ring, made of ice particles ejected by active moon Enceladus. These tiny ice particles create a broad, diffuse ring aroung Saturn. The E ring is also blue in color, which seems to fit what we are seeing here.

Ann
No guessing needed. It's most definitely the E ring. One reason for taking the photo of Saturn with the Sun completely occluded is to make the E ring stand out.