Slashdot Mirror
Titan's Smooth Surface Baffles Scientists
JazMuadDib writes "Scientists expected a few rough spots when their space drone snapped close-range images of Titan, Saturn's largest moon. Instead, the planetlike moon appears to have a bizarre, mysteriously smooth surface, and Tuesday's images have left them in a state of wonder. Read more at the Tucson Citizen." NASA's Cassini pages have a wide assortment of images and analysis. Cassini's data has already thrown scientists for loop.
There could be massive mountains and deep valleys there, or the surface could be completely flat. At this point, there's no way to tell.
Am I missing something? The title of the slashdot entry discusses the smooth surface, but I RTFA, and scientists don't KNOW... period?
In the science briefing today a number of the scientists commented on how with the radar data there are no peaks of valleys over 50 meters. The visual is hard to tell the height but with the radar they know.
I am hoping that the radar data can provide the elevation data they lack from the visual stuff.
Looking at some of the preliminary radar data (here), there's a strip 400km long, with no more than 100 meters of height variation. That's flatter than the state of Kansas!
"They redundantly repeated themselves over and over again incessantly without end ad infinitum" -- ibid.
Actually it was on Europa in 2010. This premise (well, at least the premise of a liquid ocean) was backed up by the Galileo space probe when it reached Europa. Ganymede might also have a liquid ocean, but Europa still looks like the best place to look for life, IMHO. Granted, I'm not holding my breath.
Ben Hocking
Need a professional organizer?
Cassini carries huygens, a land probe which will (hopefully) land on Titan on january 14th. There is an interesting story on ieee spectrum about an engineer who prevented the mission from certain failure.
right here
fascinating stuff. shows titan flat as a pancake for 100's of kilometers.
Among the recent images provided by NASA is a graph showing data from the ion and neutral mass spectrometer as Cassini sniffed Titan's upper atmosphere (far away from the cloud at the southern pole, if I understand it correctly). Some compounds have been identified by mass and labelled, such as hydrogen (2 Da), methane (16 Da) and nitrogen (28 Da).
However, I wonder what that unlabelled band at 7 Da (between hydrogen and methane) represents. What molecule could possibly have a mass of 7? I haven't taken a chemistry class since 1980, so please help me decode this. Are we seeing lithium ions or something?
As for the speculation that the clouds contain some "organic goo", didn't someone long ago suggest that the moon was made of cheese..?
Or maybe with "God damnit, how did this mold get on my cultures. Ok, who left the damned window open?" followed closely by "Hey, why aren't any of the germs near the mold? Hmm thats odd"
-kaplanfx
Visualize Whirled Peas
> Titan is believed to be heated by gravitation stress from Jupiter...
Titan is a moon of Saturn, not Jupiter.
605413? Yes, it's a prime.
Depends on the kind of radar, and the techniques used.
t s6006.shtml
If they're doing Synthetic Aperture interferometry (i.e., multiple pass analysis), they can get range, azimuth, and phase, which can give outstanding accuracy (see, for example, Zebker and Goldstein's Topographic Mapping From Interferometric Synthetic Aperture Radar Observations, Journal of GEOPHYSICAL RESEARCH, Vol. 91, NO. B5, pp. 4993-4999, Apr., 1986)
There's a decent online summary of the technique at http://www.gisdevelopment.net/aars/acrs/1997/ts6/
Now, since it's a spaceship fly-by, there's not as much chance for doing interferometry. You still have pretty good ranging signals. I don't know the accuracy in terms of meters, though.
I think they'll be doing SAR interferometry at some point in the project, but not yet. I think they'll do it from orbit, like Magellan did over Venus.
Eloi, Eloi, lema sabachtani?
www.fogbound.net
Many people are confusing two separate issues here: visual imaging and radar topography. On this one pass, and on each of the other passes, Cassini will get A) visual image data on large parts of Titan's surface and B) radar topography on a SMALL PART. The radar sequence is very short -- they just get a little strip of radar data at closest approach and then that's it for that pass.
OVER MONTHS AND YEARS, they will gather enough to put it together and form a complete body of INTEGRATED visual and topographic data, and then we'll get the cool flyover renderings that make us all wet our pants.
But for now they have lots of visual data, which they CAN NOT use for determining topographic details due to the lack of shadowing, and a tiny bit of radar which they CAN.
One simple rule for its versus it's
As in, University of Arizona, in Tucson. Which happens to be a leader in planetary science.
Unlimited growth == Cancer.