Date: 1/01/2014 23:17:52
From: ChrispenEvan
ID: 462500
Subject: Cassini snaps the inner planets

http://www.jpl.nasa.gov/spaceimages/details.php?id=PIA17172

On July 19, 2013, in an event celebrated the world over, NASA’s Cassini spacecraft slipped into Saturn’s shadow and turned to image the planet, seven of its moons, its inner rings — and, in the background, our home planet, Earth.

With the sun’s powerful and potentially damaging rays eclipsed by Saturn itself, Cassini’s onboard cameras were able to take advantage of this unique viewing geometry. They acquired a panoramic mosaic of the Saturn system that allows scientists to see details in the rings and throughout the system as they are backlit by the sun. This mosaic is special as it marks the third time our home planet was imaged from the outer solar system; the second time it was imaged by Cassini from Saturn’s orbit; and the first time ever that inhabitants of Earth were made aware in advance that their photo would be taken from such a great distance.

With both Cassini’s wide-angle and narrow-angle cameras aimed at Saturn, Cassini was able to capture 323 images in just over four hours. This final mosaic uses 141 of those wide-angle images. Images taken using the red, green and blue spectral filters of the wide-angle camera were combined and mosaicked together to create this natural-color view. A brightened version with contrast and color enhanced (Figure 1), a version with just the planets annotated (Figure 2), and an annotated version (Figure 3) are shown above.

This image spans about 404,880 miles (651,591 kilometers) across.

The outermost ring shown here is Saturn’s E ring, the core of which is situated about 149,000 miles (240,000 kilometers) from Saturn. The geysers erupting from the south polar terrain of the moon Enceladus supply the fine icy particles that comprise the E ring; diffraction by sunlight gives the ring its blue color. Enceladus (313 miles, or 504 kilometers, across) and the extended plume formed by its jets are visible, embedded in the E ring on the left side of the mosaic.

At the 12 o’clock position and a bit inward from the E ring lies the barely discernible ring created by the tiny, Cassini-discovered moon, Pallene (3 miles, or 4 kilometers, across). (For more on structures like Pallene’s ring, see PIA08328). The next narrow and easily seen ring inward is the G ring. Interior to the G ring, near the 11 o’clock position, one can barely see the more diffuse ring created by the co-orbital moons, Janus (111 miles, or 179 kilometers, across) and Epimetheus (70 miles, or 113 kilometers, across). Farther inward, we see the very bright F ring closely encircling the main rings of Saturn.

Following the outermost E ring counter-clockwise from Enceladus, the moon Tethys (662 miles, or 1,066 kilometers, across) appears as a large yellow orb just outside of the E ring. Tethys is positioned on the illuminated side of Saturn; its icy surface is shining brightly from yellow sunlight reflected by Saturn. Continuing to about the 2 o’clock position is a dark pixel just outside of the G ring; this dark pixel is Saturn’s Death Star moon, Mimas (246 miles, or 396 kilometers, across). Mimas appears, upon close inspection, as a very thin crescent because Cassini is looking mostly at its non-illuminated face….

more at link and lots of links to pics.

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Date: 1/01/2014 23:20:23
From: ChrispenEvan
ID: 462503
Subject: re: Cassini snaps the inner planets

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Date: 1/01/2014 23:21:24
From: Skunkworks
ID: 462505
Subject: re: Cassini snaps the inner planets

I will go to the link but that image doesn’t work here, the rings are superimposed over the planet. Takes away a bit.

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Date: 1/01/2014 23:21:46
From: wookiemeister
ID: 462506
Subject: re: Cassini snaps the inner planets

that’s an incredible picture

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Date: 1/01/2014 23:23:08
From: ChrispenEvan
ID: 462507
Subject: re: Cassini snaps the inner planets

2006 imaging by cassini

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Date: 1/01/2014 23:24:33
From: ChrispenEvan
ID: 462508
Subject: re: Cassini snaps the inner planets

when you read how they are composed you understand why they are like they are.

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Date: 2/01/2014 09:20:32
From: The Rev Dodgson
ID: 462586
Subject: re: Cassini snaps the inner planets

ChrispenEvan said:

This mosaic is special as it marks the third time our home planet was imaged from the outer solar system;

Well third time by an object originating from Earth anyway.

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Date: 2/01/2014 10:21:14
From: dv
ID: 462648
Subject: re: Cassini snaps the inner planets

That is a weird weird picture.

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Date: 2/01/2014 16:15:37
From: mollwollfumble
ID: 462830
Subject: re: Cassini snaps the inner planets

dv said:


That is a weird weird picture.

Yes. I realised when it came out in 2006 that it has to be a fake, a collage of at least two different brightness ranges.

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