Titan moon images--disappointing?

The Cassini-Huygens mission has obviously been a huge

success; I think it's a miracle that they can get stuff to work

millions of miles away, considering how often electronic toys fail

right here on Earth. With that said, can we expect Titan images

that are, well, better than what we've seen so far? Maybe it's

unfair, but the standard I had in mind was more like the Mars

rover images. I'm still blown away by the sharpness and detail

in many of those. I don't wanna sound too negative, but I was a

little underwhelmed by the technical quality of the Huygens probe

images.

 

The shots taken as it descended I understand; with the

atmosphere being what it is, it must be like parachuting into Los

Angeles on the smoggiest day of the year. But the one from the

surface--are we going to see a sharper version later? There

was early talk of one of the data channels being lost, but

apparently that got resolved. Anyone know more about the

imaging system used?

 

Here's the NASA site that has all the latest: <a

href="http://saturn.jpl.nasa.gov/news/events/huygensDescent/sh

owAll.cfm" >Cassini/Huygens</a>

I remember the video from the lunar landings. They make everything since look REAL good.

I imagine the imaging system would be at a guess at least 10 years old. Huygens was launched 7 years ago, but the technology put into it would have been quite a bit older still (typically technology built into a craft like that is "locked down" in the early planning & design phases). But more than the age factor would have been the need for minimal weight, low power consumption, and efficient (read: small) file transmission. Saturn & Titan are enormously further away than Mars!

 

Still, given all those limitations, I found the images pretty cool!

It is AMAZING that they even got this much details from such a place. There is absolutely NO comparison between Mars and Titan. The Huygens probe just revealed how harsh the terrain is and what is over there.

 

Seems like an excellent place for big oil companies to prospect from!

Forget Iraq or Iran. There is Titan with copius amounts of gas!

As I understand it the three imaging systems share real estate on a single CCD scientific imaging chip. They would've picked something known to be reliable through actual real-world use in telescope systems, I'm sure. 10 years old is probably optimistic as a probe of this type takes years to design, test, and build - more than three, certainly.

 

So far I haven't heard of any complaints by the scientists who are interpreting the data gathered by the probe. That's what counts, not our collective feelings about the aesthetics of the images.

All data (about 100 pictures and all kinds of measurements) had to fit into 3-5 megabytes, because that was about the maximum they could transmit during the 'listening time' of the Cassini spacecraft.

<p>

See this <a href="http://news.bbc.co.uk/2/hi/science/nature/4175099.stm">BBC news article where they mention 'three floppies worth of data'</a>.

<p>

Fitting all those pictures into such a small transmission (most probably without resorting to lossy compression) would get you low-res, fuzzy images.

I agree Don, the scientific achievement makes it well worth the

effort, and "pretty pictures" wasn't the goal. But was the imaging

system that much older/worse than the Mars rovers? Certainly it

was much lower light levels and nasty atmospheric conditions...

1) Miraculous: to have gotten what they got. Especially in an hour and a half window after

so many years and kilometers. Erosion channels, on Titan? Coolness.<br>

2) Disappointing: yeah, I wanted Tars Tarkas riding by on a thoat in the Mars pics, too. Or

at least Kelly Freas cover art. Got over it, eventually. Mostly. ;-)<br>

3) The images of the face and the pyramids will come later. Check the web in another few

weeks.

Face and the pyramids, Don?! :)

I think Sander has it right. The limiter was the length of operational time on the surface. It's a minor miracle they put working equipment onto the surface at all and got data back. If you could park a working probe there for a month you've got lots more opportunities than they had with the minutes available.

 

Kurt Vonnegut's "The Sirens of Titan" didn't take into account the moon's surface temperatures. :)

Disappointing?? Are you completely insane? :)

 

This thing was 20 years in the planning, seven years in the travelling, and it took these

photos and sent them back from unimaginably far away, largely without human

intervention.

 

These pictures are _mindblowing_.

Sander is correct. The probe had a very limited window to transmit data, limiting the total

amount of data that could be sent back.

A rather interesting document about the design of the Huygens Descent Imager/Spectral

Radiometer (DISR) can be found here: <a href="http://www.rssd.esa.int/SB/HUYGENS/

docs/SP1177/tomask_1.pdf">http://www.rssd.esa.int/SB/HUYGENS/docs/SP1177/

tomask_1.pdf</a>

 

<p>It's interesting to note that the first Mars rover used surplus imager units from the

Huygens DISR engineering effort.

 

<p>The Huygens had to operate in a far more hostile, cold, and dark environment than

the Mars missions. That, combined with the limited power, time and bandwidth available

during descent limited the amount of data.

Sorry if my 3) was too cryptic. Search on "Cydonia" (the locale on Mars) for more than you

want to know. See <a href="http://www.mt.net/~watcher/mars.html">here</a> for a

sample. ;-)

Thanks, Don! It sure is more than I want to know!

 

Interesting to know how there REALLY are more things between heaven and earth that can be dreamt of in cyber space!

It's good that they did not decide to land on the Europe.

:D

I've seen the images too-amazed at this incredible accumplishment. As to the image quality, you know that every ESA and NASA computer engineer is going to put their hearts into using the best graphics software around to 'improve' those images. Somewhere between science and art we'll see some lovely returns from their work. Just hold on a bit longer.

 

I sure wish Carl Sagon was still around to savor this moment in time.

Carl Sagan? Long gone since 1996.

 

We have not made any "contact",yet.

People are right that part of accomplishment is in getting *anything* back at all allowing

for the fact that this was all done using technology that is probably more than 25 years old

-- for silly comparative purposes, imagine dropping your F4 out the side of the space

shuttle with the self-timer set to your best guess about how long it will take to arrive

somewhere interesting...

 

But the real limitation on the resolution of the photos is *not* in fact the CCD it's power

consumption. Even using a directional broadcast, most of your 'message' (i.e. the photos)

is going to end up smeared across a wide swath of the solar system. So to make your

message intelligible (i.e. distinguishable from the background radiation) to the listener you

have to waste a *lot* of energy increasing the power of the transmission. And even then

you'll get a lot of interference from a very noisy (in the electromagnetic sense) universe.

 

So ramping up the power of your broadcast and covering your bases with respect to error

checking (can you hear me now? can you hear me now?) actually leaves very little 'juice' for

the message itself. Add to that the fact that all of this equipment needs to survive seven

*years* in a vacuum where even something the size of a particle of sand has the ability to

obliterate the entire apparatus (if it's moving fast enough) and altogether it's pretty

damned impressive.

 

HTH.

 

jon

He's already enjoying the view from *billions* of miles above the Earth... :>) I certainly didn't mean to take away from what they've accomplished, I'm blown away by the whole thing too. I guess the only one that really surprises me is the surface image, which seems so soft, not just lo-rez. Esp. compared to something like <a href="http://nssdc.gsfc.nasa.gov/imgcat/html/object_page/v13_vg261_262.html" >this image from Venus</a> , which was also taken under extreme conditions (+457 C and a pressure of 84 Earth atmospheres). That lander also only survived for a couple of hours before imploding. Just food for thought... And a round of applause for all the geeks who make this stuff happen!

I just finished talking about the Titan mission on TV for my day job, so I think I can shed

some light on the subject as an expert.

 

The highest resolution imager on Huygens was 160x256 pixels. The main focus of the

mission was not the pictures (though that's what the public is most interested in).

Huygens's purpose was to study the atmosphere of Titan with spectrometers, wind speed

sensors, microphones (to try to hear thunderstorms), and many other instruments. All of

this data AND the 360 pictures we got back had to be sent in a three-hour window before

the Cassini "mothership" got out of range.

 

On top of that, the probe was trying to stay warm in -300 degree (F) conditions and send

all of this information back through an atmosphere eight times as thick as Earth's (and one

that is thick with methane "smog"). The probe was encased in ten inches of foam and had

35 radioactive heaters, but it was only designed to last THREE MINUTES on the surface

before the batteries froze. It lasted much longer, thanks to the good engineering from the

European Space Agency.

 

As for comparing it to the Mars pictures, that really isn't fair for a number of reasons. First

of all, the best Mars rover cameras are only one megapixel. The amazing pictures you see

are the result of stitching together about one hundred smaller pictures. The Mars rovers

are sitting still and have all the time in the Solar System to send back their images. Low

shutter speeds and a six-wheeled tripod help too!

 

Huygens was falling through the atmosphere of an alien world we knew little about, being

buffeted by wind and blocked by clouds and smog. The light levels on Titan are about

90x dimmer than a moonless night on Earth. It had to send back tremendous amounts of

data AND SOUND, and one of the communications channels wasn't working properly.

 

With all of that, these images are amazing!

If you are not happy with the images, grab the RAW files and process them yourself. Check out this site, where people have done just that:

 

http://anthony.liekens.net/huygens_static.html

 

Regards, Ross

To Adam:

 

Great comments!

That's a cool link Ross, thanks. And tip the hat to Adam, that's

the best summary I've seen anywhere. :>)

<P>The raw images are really work a look (though you have to sift through a lot of

"boring" ones to find the gems). They can be found at <a href="http://

esamultimedia.esa.int/docs/titanraw/index.htm" target="_blank">http://

esamultimedia.esa.int/docs/titanraw/index.htm.</a>

 

<P>I'm glad my summary helped. It's my job to talk about this stuff, but thanks for the

complement anyway!