Posted on 08/23/2014 7:58:55 PM PDT by SunkenCiv
Explanation: Where should Philae land? As ESA's robotic spacecraft Rosetta circles toward Comet 67P/ Churyumov-Gerasimenko, a decision must eventually be made as to where its mechanical lander should attempt to touch-down. Reaching the comet earlier this month, Rosetta is sending back detailed pictures of the comet's unusual nucleus from which a smooth landing site will be selected. Pictured above, near the image top, the head of the comet's nucleus shows rugged grooves, while near the image bottom, the body shows a patch-work of areas sometimes separated by jagged hills. Some of the patch-work areas apparent on both the head and body seem to have fields of relatively smooth terrain. In the connecting area called the neck, however, visible across the image center, a relatively large swath of light-colored smooth terrain appears, punctuated occasionally by large boulders. Rosetta is scheduled to release Philae toward the dark mountain-sized comet nucleus with an anticipated landing date in November.
(Excerpt) Read more at 129.164.179.22 ...
[Credit: ESA / Rosetta / MPS for OSIRIS Team; MPS/UPD/LAM/IAA/SSO/INTA/UPM/DASP/IDA]
Incredible image...
I captured this lunar image recently...It was actually video, where I processed 800 frames into the 40 best, and combined them all, or stacked them. Not quite Rosetta quality, but not too bad..
was it two asteroids that got smushed together at some point?
“Smushed” being a very technical term
Very strange. Nowhere near enough gravity to keep all those rocks sticking to it, let alone to have what looks all the world like a dust or small debris slope at an angle of repose.
“relatively large swath of light-colored smooth terrain appears”
I will bet that’s where the tail comes from - the deposit of ices. This isn’t a “great comet” and there doesn’t seem to be much of those ices left. This should be interesting to watch as the comet comes closer to the sun and warms up.
nothing to knock the rocks off either
Well the comet is spinning, so there's that. Any movement would fling objects off of it because there's nothing to keep them there. Also, the question arises as to how they got there in the first place without gravitational attraction. Maybe electrostatic? Comets go way far away and then return to the inner system and go around the sun. If there is a charge differential of some kind between the two poles of the orbit (i.e. the sun vs. deep space) then maybe that's it. I wonder what kind of EM field readings the spacecraft is getting from it. Weird object. NASA should look for a hatch...
At the moment, there is nothing to move loose material off the comet’s surface. It has a mass of ~1 X 10^13 kg. Escape velocity is ~0.5 m/s.
It does not take much gravity in space to hold a object by my way of thinking, and I am not a scientist.
All you need to be is the biggest mass in the vicinity. The small stuff will come to you.
I wonder what would happen if you had a fat guy floating about..
Here is a pdf of a paper concerning how loose dust clings to asteroids.
http://arxiv.org/pdf/1002.2478v1.pdf
Thanks, it’s nice!
The photos keep getting better and better,
simply amazing. I could see a landing on the narrow waist
but wonder how communications would be affected.
Plenty of dust or ice on the rest of it to land on
also.
Will be following this closely over the next
months.
t.
The amount of small detail on the surface on one of these two hunks of debris joined as if as one is pretty amazing, and I agree, their transit should be very interesting.
There’s plenty of gravity to do that, there’s just nothing large enough that’s near enough to entice the pieces away.
;’)
There appears to be quite a number which are just that — once these oblong piles of space crud get studied close up, they wind up being two good-sized things that are held together by mutual attraction and lack of competition for their affections.
Thanks!
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