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Rosetta, Philae and Comet 67P/Churyumov-Gerasimenko.

Vicomt

By Vicomt
in Science & Spaceflight

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Sky_walker

Sky_walker

Posted
Posted (edited)

I wouldn't call it a "best guess" - more like: a "guess", period. People making an images showing black (yes, a solid black color) are closer to truth than what this image is showing.

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Looks like American conspiracy theorists just discovered European Space Agency! Seems like the latest PR offensive from ESA really did a great job raising public awareness about it's existance. Well done ESA, well done.

Anyway, here's what US UFO freaks came up with: [Removed by the Moderation Team]

Edited by sal_vager
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Aethon

Aethon

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Posted (edited)

Ok, how about some amateur, dumb guy analysis/questions.

The jet seems to originate from the neck of the 'duck'. Could this be from an unusual differentiation in the early solar nebula, where the interior and part of the exterior were composed of lower melting volatiles? Or is it like the way a snowbank melts ( We don't haaave snowbanks where I live so I don't- Well good for you! :huh: ), with the darker higher, melting point material drawing in the solar radiation, melting the lower volatiles (water) away and collapsing under gravity to fill the voids, forming a sort of higher volatile crust?

Reflections? Comments? Discussion? Abusive ire?

It would be super cool if Cherry/Gerry split in two while Philae is on alive on the surface.

Cherry/Gerry in 3-D videos :

http://www.universetoday.com/115009/rosettas-comet-in-thrilling-3-d/#more-115009

Edited by Aethon
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Rune

Rune

Posted
Posted
Ok, how about some amateur, dumb guy analysis/questions.

The jet seems to originate from the neck of the 'duck'. Could this be from an unusual differentiation in the early solar nebula, where the interior and part of the exterior were composed of lower melting volatiles? Or is it like the way a snowbank melts ( We don't haaave snowbanks where I live so I don't- Well good for you! :huh: ), with the darker higher, melting point material drawing in the solar radiation, melting the lower volatiles (water) away and collapsing under gravity to fill the voids, forming a sort of higher volatile crust?

Reflections? Comments? Discussion? Abusive ire?

It would be super cool if Cherry/Gerry split in two while Philae is on alive on the surface.

Cherry/Gerry in 3-D videos :

http://www.universetoday.com/115009/rosettas-comet-in-thrilling-3-d/#more-115009

I see it more of a result. Since the contact region between the two joined bodies seems to have the lightest material (the one more likely to have moved towards the center of mass when the two original bodies aggregated), it sublimates more and over time thins the region until , I imagine, some gravitational collapse rearranges the whole thing.

That is supposed 67P-Churyumov-Gerasimenko is a contact binary created when two independent objects got to close together like the Rosetta teams believes, of course. And mostly my not so very well informed opinion. But it makes sense to me.

Rune. Good thing is, we'll know more about it soon! :)

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Mr Shifty

Mr Shifty

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Posted
Is the more reflective material rock or ice(or do they not know yet)? I'm no geologist, but it looks like sand so I would have to assume it's dust/ice particles from impacts and rescooping up it's own coma particles(does that happen?), maybe?

Sand, I'd think, would be a little hard to characterize from this distance. Because there's no reference, I think you're tricked into thinking you see more detail than you really can. Here's the same image of the comet, approximately at scale against Manhattan Island.

ELUi9FS.png

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lajoswinkler

lajoswinkler

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Is the more reflective material rock or ice(or do they not know yet)? I'm no geologist, but it looks like sand so I would have to assume it's dust/ice particles from impacts and rescooping up it's own coma particles(does that happen?), maybe?

You can't determine which material is more reflective from this image, because you see one photo of several surfaces under different angles. Some surfaces are in shadow. Also, it's highly overexposed so you see coal black as ash gray.

We do know, however, that the temperature of the surface is higher than expected.

Regarding the boulders, each of these prominent ones are the size of a 3-4 storey building. Like a mall or a smaller museum.

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Mr Shifty

Mr Shifty

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One of the boulders in higher resolution.

Don't be fooled by the "smooth surface". It might be quite rough.

Beautiful image. Here's an image of the boulder next to an American football stadium to get a perspective for how big it is.

1AmnOGo.jpg

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sgt_flyer

sgt_flyer

Posted
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sooo, Philae release and landing time are displayed on the ESA website :)

for both the main site (J) and the backup site © the separation and landing would be on november 12.

for Main site landing : separation at 08h35 UTC, with a landing more than 7 hours after that - the confirmation signal will make 28 minutes and 20s to get to us - so we will have confirmation near 16h00 UTC.

for backup landing site : separation at 13h04 UTC, with a landing 4 hours after that - we'll have confirmation near 17h30 UTC in this case.

final confirmation of the primary landing site should be made on october 14.

http://www.esa.int/Our_Activities/Space_Science/Rosetta/Rosetta_to_deploy_lander_on_12_November

Edited by sgt_flyer
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Sky_walker

Sky_walker

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Posted
Haha, wow. They even got the comet at exactly the same rotation point and the same angle with respect to the sun as in the previous one.

These are shots for PR department so they can choose when photo is taken to get the most attractive angle.

The success and popularity of the first shot gave a green light to the follow-up.

One fun fact about this image - it's taken with wide-angle camera - field of view is approximately 60 degrees, which is roughly identical to 20mm lens on a consumer-grade DSLR camera (APS-C sensor). Rosetta is VERY close to the 67P.

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lajoswinkler

lajoswinkler

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Posted

Around 9900 metres from the surface, and 0.63 m/px for the surface closest to the camera.

http://www.esa.int/spaceinimages/Images/2014/10/Comet_on_15_October_NavCam

Comet_on_15_October_NavCam_node_full_image_2.jpg

I wonder if the grains we see are boulders the size of a large TV or perhaps more spiky features. Something tells me Philae will be having difficulties landing. I'm expecting something similar to karst.

Shilin_Stone_Forest_01.JPG

Except it wasn't developed by rain, but by heterogeneous sublimation.

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