Where would metaphorical Lagrangian points be for Rhea? Is it possible that they are at such a range that a modest impact would chuck material out at a velocity to reach, and then disperse around them?

Doug

I'm reminded of : http://www.the-reel-mccoy.com/movies/2001/...onstersInc1.jpg

Yeah - the Hawking program was great - the Horizon was meh, I couldn't maintain interest.

Doug

This thread is at 12.4 meg of attachments and growing rather rapidly - far more so than any discussion elsewhere. Someone ( aka me and Joe ) has to back that up, move it to the new server, and then start backing it up from there. Unless it's a truly exceptional image, can you exhibit a bit more restraint (or compression, or resizing in a downward direction), especially with the artistic impressions that whilst very pretty, probably show less detail than their source material.

Doug

For those with access, this months Sky at Night (the extended BBC4 mix) is on www.bbc.co.uk/iplayer (go to channels, then BBC4). Chris Lintott visited the asembly facilities for LCROSS and LRO - and they actually imaged Chris and the scientists he was interviewing with LCROSS, with two nIR cameras, one sensitive to water, one not - so they can subtract the two images and identify where the water is. They were holding a bottle of water and it worked - very clever!

Doug

Think about it. Jason spends all his time look at Io images - and it's like a volcanic red-light district. He looks at ONE Mars picture...and bam. Only plausible explanation.

MSL - with an actively guided entry will be smaller ( something like a 10km circle ) - but Phoenix is going to be basically the same as MER I would expect. Something like 80k x 20k - someone may be able to put my right on that though.

Dog

Attached, my unscientific ( tweak till looks nice ) method for taking the IRB images from the IAS viewer ( with all channels set to be unstretched at 0 to 255 ) and making them look a little more 'normal'.

If you go to image > adjust > channel mixer - you should then be able to load this, and it'll have a stab at it.

This is a bit better than the one I used to do the four avalanche images - I'll revisit them in a bit ( edit - now done, they look MUCH better )

If anyone knows a more scientific method for the artistic types, chip in

edit: this only appears to work for that image - that polar image. The ice providing, I assume, a white point.


Doug

Well

"Latitude (centered): 68.2 ° Longitude (East): 233.2 °"

From http://hirise.lpl.arizona.edu/PSP_007207_2485 - which is inside the ellipse.

If you said 68 / 233 - you couldn't be considered wrong.


http://www.nasa.gov/images/content/183675m...label-hires.jpg

and

http://www.unmannedspaceflight.com/index.p...amp;#entry98551 for more.

Doug

Well - from an old HiBlog entry

"What is the difference between “RGB” and “IRB”? The RGB products are different than the IRB products in that the IR channel has been replaced by a “synthetic blue” layer that creates an image that is somewhat closer to natural color. In many of the images, the infrared band does not contribute a lot of information. The bands in this product have also been stretched to provide better contrast. In other words, the RGB images are more aesthetic. The IRB product is a science product. It contains the IR, RED and BG layers."

I'll bet they made that from R and GB.

My technique - roughly - http://www.unmannedspaceflight.com/index.p...t=0#entry110381

Meanwhile - there IS disparity between the channels. Between the IR and the GB, I think there's motion. What's the orbital speed of MRO - we can calculate the speed at the front of the big one. It's certainly several pixels worth - if my 2.5km/sec guess is right, we're looking at several m/sec.

OK - more maths - I've found figures of 3 to 3.25km/sec - Let's call it 3.14 (what a nice number)

Assuming that the IR and the GB CCD's are, measured in pixels of CCD width, something like 2100 pixels apart. Very roughly. Thus 525 metres apart. Thus, 0.167 seconds.

So - one pixel difference, is 25cm in .167 seconds, or just about 1.5m/sec

Attached - a flick between IR and GB - I can see maybe 10 pixels of motion at some points on that 'front' - so 15m/sec. Other places, more like half that Very very rough maths - please pick holes in it - but I think we're talking a true ballpark figure there.


Doug

I saw the same thing here - http://en.wikipedia.org/wiki/Fingal's_Cave - it's astonishing stuff.

I figured out what caused them. It was the shock of Jason looking at a Mars image that resonated throughout the solar system and expressed itself as a seismic event on that ridge. If you hadn't have looked at it - there wouldn't be any landslides

Doug

Here are the 4 I can find - in my tweak-IGB-to-make-it-a-bit-more-marslike guestimation. THe whites are a bit blue, but other than that I like it. North is 77 degrees clockwise from straight up, or 13 degrees above 'right'. These are numbered 1-4 going from East to West. There's one more, a little more East, but I think it's 'over' - its a lot more feint, perhaps it happened a few mins before the image was taken

There is a slight delay, I think, between the channels - but it'll be very small. Look at the CCD layout, ( http://hirise.seti.org/epo/hirise_lesson1_files/image017.png ) the ir, r and gb filters are perhaps one ccd's width apart, in the direction of motion - so 2000 pixels, 500 metres. THey start and stop the channels so they line up - but there will be a tiny delay because of the orbital speed. I can't recall what that is ( 2.5km/sec rings a bell- may be WAY off ) - so if that's right, 500m will be a 1/5th of a second. So, every pixel difference, would be 1.25 m/sec - if that 2.5km figure is right. I don't think it is - and it'll vary with altitude anyway.

Doug

Assuming it's nothing but pure water. Some of the flows ARE Spectrally different - they're bright to MOC, when the surrounding terrain is darker.

I'm not saying that Malin et.al. proposal is wrong. I'm not saying the new HiRISE theory is right - I just like to see discussion, and I don't like to see people pinning their 'hopes' or 'desires' onto one 'side' of an argument. The moment one has a pet theory ( and that's what I think this has become to many ) then scientific integrity and the honesty of interpretation is slightly compromised.

Doug

Racing a DB9 to Monte Carlo, proving the rocket-car darwin award myth is bull.

Sold.


:0

Give me Sky marathons of Mythbusters, Top Gear, A Car/Plane/Bike/Chopper is Born, Anything with Ray Mears. Black Sky - the Discovery documentary on SS1 I could watch all day, every day. Today - feeling a bit lethargic, I watched all of Clarksons 'Inventions that Changed the World' - they were BRILLIANT. His documentary on the Greatest Raid of All Time was just astonishing television.

I used to watch ER when I was a student....and....I confess...a LOT of Caroline in the City, Will and Grace, and Frasier.

Maybe I'm in a minority - but I find, on the whole, most SciFi to be, to be honest, crap.

All the Star Trek stuff - didn't like it. Star Wars - all dreadful. Dr Who, Torchwood, bleurgh. I like Lost - but that's about it. Heroes, Stargate, Firefly. I like Stephen Baxter's Voyage and Titan, and to a lesser extent, Moonseed. I've never read a A.C.Clarke novel - and while I have 2001 A Space odyssey on DVD, I don't think much of it. The thing is, via blogs etc, it seems that just about everyone who like science, likes science fiction.

Oh - and Cloverfield - my comments over at Phil's www.bautforum.com :

"It was pure, unadulterated arse gravy of the sloppiest kind from start to finish. Sorry. The acting was dreadful, the dialogue hideously predictable, the direction was self indulgent and the plot line obvious after the first 30 seconds with what is on screen with the opening credits. The hand-held camera was a gimmick, and a nausea inducing one at that ( I had to look away for a minute or so, on several occasions, to subdue the genuine nausea I was feeling ). This brat's got an amazing HD camera that can survive a virtual apocalypse...and it doesn't have image stabilization?

It was too bad to be any good, and it wasn't set up to be tongue-in-cheek like an episode of Dr Who.

On the upside - it was quite short."

Independence Day is made watchable by two great lead characters - but the St Crispens day Henry V speech ripoff by the US President was grating. Armageddon is made unwatchable by Willis and vulgar over sentimentality and nationalism. Space Cowboys was just dire. Deep Impact was OK.

Doug

So 'it looks like' then - and to be fair, that's the conclusion Malin et.al. made from MOC imagery as well. No offense, but results of CFD study of HiRISE generated DEM's holds more water (pun intended) at this stage, imho.

The problem I have with the water theory is this. Where's it coming from? To be a squiring gun for millions, tens of million, hundreds of millions of years or more - to be doing it for as long as Mars has been as it is today - surely, any such reservoirs would have been exhaust in the significantly geological past. It's a one shot activity. Squirt - boil - evaporate - gone. I don't think we can realistically expect a water cycle to put that volume back into the soil.

What's going to be most interesting (and I'm surprised we've not seen it yet) is CRISM results of the 'outflow'.

In one forum I've been called a water-on-mars nut, and on another, a dry mars conspiracist. All I'm really after is facts and data to help us find out what Mars is really like.

On what basis?

Oh come on, no mention of that frankly exquisite early performance by Caroline in the City's Lea Thompson in Space Camp?

Doug

I'm not aware of any launches actually FROM EAFB. I may be wrong though.

Doug

It's up. For slightly circuitous and complex reasons, we now have dual 3 Ghz grunt inside the box, for the same price. ( Thanks Dan! ) - I've logged into it, poked around, all is good!

We're getting it checked out for performance, security and stability next - and then we'll start dumping stuff on it for testing.

Actually LCROSS does take a long route. It's a couple of months longer than LRO, involving Lunar flybys to target for the south pole.

Doug

FLAT : (Four Letter Acronym Telescope)

Or, slightly more seriously, the Feenberg Telescope, or the Kemble telescope.

Doug

You just need the pizoelectric techniques I blogged about at Valencia some time ago. A very thin film, very low mass, very low power. Turn it on and the dust just goes away - it's amazing.

http://marstech.jpl.nasa.gov/content/image...amp;TaskID=2300


Doug