APOD: Rosetta's Farewell (2016 Oct 01)

Comments and questions about the APOD on the main view screen.
epitalon
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Re: APOD: Rosetta's Farewell (2016 Oct 01)

Post by epitalon » Sat Oct 01, 2016 4:22 pm

I have a couple of questions :

Was it was not possible to let Rosetta sleep for some years until the comet returns ?
Would it stay in orbit around the comet all this time ?
Would the battery or some other component be damaged by the cold at Jupiter's distance from the sun ?
So would it be a dead spacecraft when the comet returns ?

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Re: APOD: Rosetta's Farewell (2016 Oct 01)

Post by ta152h0 » Sat Oct 01, 2016 4:38 pm

I have often wondered, while sitting on a stool having a beer and observing the oter half of humanity, what is the actual interaction between the atoms in my seat and the actual atoms of the stool. I am sure one atom has arepelling force on te other, and yet they stick together to make " wood " and " flesh " and the aggregate force probably equals my weight.( I like your real time spell checker )
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Re: APOD: Rosetta's Farewell (2016 Oct 01)

Post by Jim Armstrong » Sat Oct 01, 2016 5:05 pm

I was also struck by how "planetary" the terrain in the photograph appears.
I expected a 67P article, but immediately assumed the subject was Martian when it came up.
Or maybe the box canyon in the Mojave where we used to shoot our .22's 60 years ago.
I have to say that I am astounded by, and proud of, the ongoing results of America's investment in NASA. And not in the DoD.

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Re: APOD: Rosetta's Farewell (2016 Oct 01)

Post by Seedsof Earth » Sat Oct 01, 2016 5:26 pm

There is one object on the comet in this image that is unusual in that it almost looks artificial (but I'm sure it is not). It is located in the upper left corner of the lower right quadrant of the image, and appears to be a pointed stake poking up from the ice, and is casting a shadow to the left. Just to the left of the "stake" are two large, flat boulders (for reference). Do scientists have any idea what it might be?

Further, concerning the crag at the top of the image, I would assume that contrary to what many might imagine, one could not leap off the top of the crag and expect to land somewhere down along the "talus" slope. Since gravity "flows" to the greatest mass, it would not pull one down to the talus slope, but rather to the wall of the crag where the gravimetrics are theoretically stronger. In fact, there is probably stronger gravitational pull toward the two lobes of the comet rather than toward the center, or "neck" of the comet. With this in mind, I am assuming that the talus is not talus at all, but rather loosely packed rubble, while the rubble that forms the cragg is more tightly packed, and less "loose" looking due to the stronger gravity within the structure of the cragg. Would you agree with this? If not, please enlighten me.

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Re: APOD: Rosetta's Farewell (2016 Oct 01)

Post by rstevenson » Sat Oct 01, 2016 5:41 pm

Seedsof Earth wrote:There is one object on the comet in this image that is unusual in that it almost looks artificial (but I'm sure it is not). It is located in the upper left corner of the lower right quadrant of the image, and appears to be a pointed stake poking up from the ice, and is casting a shadow to the left. ...
I think what we're seeing is a V-shaped shadow of a rock which is covered in the same material that covers the plain. See this pic...
a bit of 67P.jpg
The object you're asking about is in my top-right red circle. Compare it to an obvious rock which is in my bottom-left red circle. If that latter object had the same fine material covering it, all we'd see would be its V-shaped shadow line, similar to what we see (I think) around your object.

Rob
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Re: APOD: Rosetta's Farewell (2016 Oct 01)

Post by Boomer12k » Sat Oct 01, 2016 5:52 pm

Craggy bit o' rubble...

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Re: APOD: Rosetta's Farewell (2016 Oct 01)

Post by neufer » Sat Oct 01, 2016 6:13 pm




ta152h0 wrote:
I have often wondered, while sitting on a stool having a beer and observing the oter half of humanity, what is the actual interaction between the atoms in my seat and the actual atoms of the stool. I am sure one atom has a repelling force on the other, and yet they stick together to make " wood " and " flesh " and the aggregate force probably equals my weight.
Your seat and the stool induce mutual electric dipoles which produce a van der Waals attractive force that goes as the inverse of the distance to the seventh power.

However, after 'contact' the quantum mechanically identical electrons in your seat and in the stool generate a much stronger repulsive force to counteract both gravity & the van der Waals attraction.
Art Neuendorffer

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neufer
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Re: APOD: Rosetta's Farewell (2016 Oct 01)

Post by neufer » Sat Oct 01, 2016 7:42 pm

Art Neuendorffer

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Re: APOD: Rosetta's Farewell (2016 Oct 01)

Post by geckzilla » Sat Oct 01, 2016 8:58 pm

Jim Armstrong wrote:I have to say that I am astounded by, and proud of, the ongoing results of America's investment in NASA. And not in the DoD.
ESA. This was not an American project. Still something to be proud of as a fellow human being.
Just call me "geck" because "zilla" is like a last name.

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Re: APOD: Rosetta's Farewell (2016 Oct 01)

Post by daddyo » Sun Oct 02, 2016 1:33 am

Rob, That tree is an imager artifact. I was fooled by it a while back in similar images.

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JohnD
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Re: APOD: Rosetta's Farewell (2016 Oct 01)

Post by JohnD » Sun Oct 02, 2016 9:07 am

Many above have repeated my request for a discussion on how the process outlined by neifer leads to strata and the other planetary formations. Anyone?
John

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Re: APOD: Rosetta's Farewell (2016 Oct 01)

Post by nebosite » Sun Oct 02, 2016 3:00 pm

Tekija wrote:What are those many white spots?
Ditto! What are those super bright spots? Are the similar the the bright material on Ceres?

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Re: APOD: Rosetta's Farewell (2016 Oct 01)

Post by FLPhotoCatcher » Sun Oct 02, 2016 3:08 pm

nebosite wrote:
Tekija wrote:What are those many white spots?
Ditto! What are those super bright spots? Are the similar the the bright material on Ceres?
I'm no expert, but some of them could be caused by charged particles from the sun, and/or bad pixels in the sensor. Note that there is one in the 'sky' to the far left, and another one just above the edge of the comet, left of center. Or they could be space puffins.

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Re: APOD: Rosetta's Farewell (2016 Oct 01)

Post by FLPhotoCatcher » Sun Oct 02, 2016 3:24 pm

If the bright spots are not photo artifacts, I suppose they could be areas where out-gassing water vapor is condensing into ice (frost). Most of the spots are near crevasses or shadowed areas (colder areas where out-gassing is more likely), so that seems to support the idea. And maybe the two spots in the sky are chunks of ice that have been 'blasted' upward by the vapor pressure.

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Re: APOD: Rosetta's Farewell (2016 Oct 01)

Post by DavidLeodis » Sun Oct 02, 2016 7:58 pm

It has been a fascinating mission :clap:. In the words of the 1971 Alan Price and Georgie Fame 'Rosetta' lyrics "Rosetta are you better, are you well, well, well" she sadly is not well anymore.

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JohnD
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Re: APOD: Rosetta's Farewell (2016 Oct 01)

Post by JohnD » Sun Oct 02, 2016 9:38 pm

Just watched the "Sky at Night"'s Farewell to Rosetta, on BBC TV. If you get a chance, do watch it. It gave the Mission Scientists the opportunity to explain the reasons WHY they have crashed the spacecraft, mainly that it is aging - it's been in space since 2004, was losing power and was about to go into conjunction with the Sun so that we would lose contact anyway - and that this strategy would get data that could not be collected any other way, not only pictures but on gases near to the comet and on it's gravity.

But despite that, scientists are human, and several looked ready for a good cry when the signal was lost.
JOhn

PS Here's ESA's own version: http://www.skyatnightmagazine.com/news/farewell-rosetta

PPS Jim Armstrong, NASA has done much, but this achievement is by ESA, the European Space Agency.

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Re: APOD: Rosetta's Farewell (2016 Oct 01)

Post by Fred the Cat » Mon Oct 03, 2016 6:30 pm

Looks are deceiving peering at the surface of 67P. This 4.6 billion year old relic appears a combination of hard and soft surfaces although it was described as "very, very fluffy". With much learned from this rendezvous and landing what would ESA do different next time so a lander wouldn't "skip" off like water off a duck's back?
Freddy's Felicity "Only ascertain as a cat box survivor"

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Re: APOD: Rosetta's Farewell (2016 Oct 01)

Post by JaxJoe » Mon Oct 03, 2016 11:50 pm

Jim Leff wrote:I'd imagine that our descendants will be extraordinarily interested in salvaging and examining this next time it circles back. Even wrecked, it will be a far better preserved example of 21st century tech than anything on earth. Imagine if the ancient Egyptians had crashed a spacecraft on a comet soon to circle back; we'd be extraordinarily excited to take a look!

So two questions:

1. When's the next approach to the inner solar system?

2. How badly did we crash it? I'm assuming, given weak gravity, that it wasn't totaled.
I am assuming that given that velocity at impact, it is totally destroyed (like Brad). I forgot to pay that extra premium to cover "full replacement" costs... Does that mean that I don't get a new car? Just three-wheels instead of four...one-third of a car....That is, all I paid for. Why should I get the whole car?

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Re: APOD: Rosetta's Farewell (2016 Oct 01)

Post by Chris Peterson » Mon Oct 03, 2016 11:57 pm

JaxJoe wrote:I am assuming that given that velocity at impact, it is totally destroyed (like Brad).
As noted above, the damage was likely very minimal.
Chris

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Re: APOD: Rosetta's Farewell (2016 Oct 01)

Post by neufer » Tue Oct 04, 2016 5:06 am

Click to play embedded YouTube video.
Click to play embedded YouTube video.
Chris Peterson wrote:
JaxJoe wrote:
I am assuming that given that velocity at impact, it is totally destroyed (like Brad).
As noted above, the damage was likely very minimal.
Art Neuendorffer

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Re: APOD: Rosetta's Farewell (2016 Oct 01)

Post by Fred the Cat » Tue Oct 04, 2016 2:06 pm

To be continued... A nice place to visit but would you want to live there? At least you would swing back by but how would you ever get the smell out. :cry:
Freddy's Felicity "Only ascertain as a cat box survivor"