I would like to open this new topic with some Mars images that I obtained using a Philips ToUCam Pro 740k and a telescope. It's really amazing what you can do today with these webcams, a moderately sized telescope and some image processing.

You simply have to unscrew the webcam's lense and fit an appropriate adaptor to attach the cam to the telescope. In this case I used a refractor with 20 cm aparture and a focal length of 3 m. It's the main telescope of Hanover's astronomy club (German homepage) that I am a member of. Additionally I used a 6x barlow lens yielding an equivalent focal length of 18 m.
After finding Mars and focusing, I usually record AVIs which are later split into seperate images (frame rate of 5 Hz).
Then I take 600 frames (2 minutes) and average them with a program called "Giotto 2.0". That program also allows to use various filtering routines to enhance details in the images.
The first image (from left to right) is a raw image, the second the average of 600 frames. To that second image, I apply butterworth and other filters. The resulting images are processed (layers, color adjustments etc) in Photoshop to obtain image 3. A bit of unsharp masking finally yields image 4.


This image is from 22 September (4 UT) The south polar cap is visible to the upper right, Syrtis Major is the large dark area to the lower right. The bright area below the south pole is the Hellas basin. The north pole is veiled by clouds. All the dark areas are not topographic features, but merely differently colored soil. Such detailed images are only possible if the seeing is exceptionally good.

I took images over a period of more than an hour and generated a GIF-animation from them (29 frames, 2:58 UT - 4:03 UT):

Full resolution (900 kB)
From the rotation you can see that the visible structures are real and not artifacts from processing.

One pixel is equivalent to 0.08 arc seconds (~ 33 km). However, the smallest structures visible are certainly larger than that.

Michael

Love the animation - that is lovely.

That is some amazing stuff!

Very well done!

[Old Fart]
Why, back in my day you spent thousands of dollars on a CCD and processed your way in a blizzard on ice, uphill (both ways) for a bunch of fuzzy images. Nowadays some punk with an $80 webcam comes along and blows you out of the water!
[/Old Fart]



Seriously, the state of amateur digital imaging has progressed incredibly over the last 5-6 years.

Very nice images, MichaelT!

Wow, that is quite impressive, especially the smooth animation. I wouldn't have guessed it was possible to get imagery that good with (I'm guessing) relatively inexpensive equipment. Nice work.

I wouldn't rate a 20 cm refractor as inexpensive...

I was guessing. I've never even looked into buying any telescope equipment. I'll take your word and forget the 'relatively inexpensive' part - it's still an impressive animation.

Thank you for sharing MichaelT, it was interesting to see the difference from raw to finished image, and yes I liked the animation too, quite amazed in fact.

WOW!

I saw some *really* incredible images in German astronomy forums that were obtained with 14-18" mirror telescopes by some "amateurs".
What amazes me the most is that all the information visible in the final image is already there in the second I wonder what will be possible in 10 years time...
And you don't need a 20 cm refractor. I saw some very nice images from people with every-day 20 cm Schmidt-Cassegrains which are not that expensive.

Michael

The amount of detail you got is truly astounding. Great work!

My only constructive criticism is that the dark areas ought to be greenish-grayish, instead of purplish...

-the other Doug

You are right. I set the tonal correction of the webcam to "auto" and thought I could change the colors appropriately later. I was wrong. No matter what I tried, something always looked strange, either the dark or the light areas.

Michael

You might be interested to know that essentially the same technique (attaching a simple digital camera to a relatively cheap spotting scope) has revolutionized bird photography in the last few years. This is known as "digi-scoping", perhaps a useful term in astronomy too?

tty

What is interesting to me is that you, an amateur using today's fairly common equipment, have made an image that astronomers of the past would have given their lives for. If your images would have been available in 1877 when Schiaparelli made his map, or in 1910 when Lowell was talking about irrigation systems on Mars, you could have proven that there were no canals.

I wonder what year it was that we did actually prove that there were no canals. The Mariners put the nail in the coffin, but were there ground images that pretty much proved it before?

Scott

Scott:

Although visual observers did (quietly) report seeing craters and the like on Mars under *very* special circumstances, no emulsion-based photography ever seemed to show much more than a blur. Think of all the hundreds of frames which are tweaked to get one good image with a webcam, and then do the reverse, fuzzying them to death, and that's what we used to see.

Have a look at Sky and Telescope November 2005 p64 for an intriguing story about the visual observations made by John Mellish 90 years ago. He's not the only person who saw surface detail, either!

Bob Shaw

I remember the time clearly, and prior to the Mariners the best images as those shown in National Geographic did not show enough detail to make any conclusion about the surface of Mars.
So you are absoluterly correct in your reply Bob Shaw.

The idea of canals was however less fashionable by the time prior to the Mariners since many new visual observers had published reports they could not find any, so the idea of a 'dying race' on the planet was quite far from mainstream.
Many thought that the changing colour seen on the surface was sign of some kind of simple vegetation such as lichens, and since the atmospheric pressure was thought to be many times higher, perhaps even 100 mB there were some speculation about animal life such as insects also. But canals? No I got the impression back then that a majority of astronomers / scientists didnt believe in any at that time.

Though if you find a copy of the December, 1967 issue of National Geographic Magazine, the article on Mars discusses the idea that the canals may be natural features and showed an example of straight lines made by natural causes on Earth.

And when Mariner 4 took its 22 images of the Red Planet in 1965, there was discussion about the two straight lines faintly seen in famous Image 11 crossing the large crater that later was given Mariner's name.

So canals were still being debated even in the late 1960s, though certainly nothing like even a few decades earlier.

If only the early Mariners had imaged the volcanoes and canyons, we probably would have had humans on Mars by now.

Yes you are correct there, when reading National Geographic which I did view that discussion as a kind of compromise effort to please readers of the two camps.

Personally I kept an open mind but thought that some of the lines very well might be for real being rays from impacts like Tycho that had spread dark material on the surface in raylike patterns. (Most likely proposed in some magazine I did read at the time but no longer remember) If that had been correct they would not have been 'canals' of course.
At the same time as being cautious about the idea of any lines I as so many others certainly was on the bandwaggon of believing in plant life, a fact that only show how badly misleading hopes and wishes can be.

MichaelT and your colleagues in Germany:

Great work!

Glenn

The Mariner 6 and 7 approach images in the summer of '69 essentially put the nail in the canals coffin. The narrow angle images were taken through a yellow filter and should have had perfectly decent sensativity to features "seen" at several times lower resolution to AT-BEST comparable resolution from Earth, and with few exceptions, like a stubby dark line in Coprates (part of Valles Marineris), the canals just weren't there.

One thing that gets constantly repeated is the false "factoid" that the 1969 Mariners showed nothing but the same cratered dirtball that Mariner 4 showed. Though sun angles were high and images were noisy, Mariner 6 discovered the chaos regions at the east end of Valles Marineris and these were widely and accurately interpreted as collapse features, possibly involving permafrost or vulcanism. Mariner 7 discovered complex features of unknown origin in the south polar cap, attributed to unknown polar processes, and caught the first glimpse of the polar layered terrain of the permant south polar cap. And Mariner 7 also observed rough terrain on the west rim of the Hellsa basin, a series of ridges inside the basin rim, and "featureless terrain" on the basin floor (probably concealed by dust haze), which the spectrometers correctly identified as sharply lower than the plateau of the southern cratered highlands outside the basin. They couldn't identify it as an impact basin, but they did identify it as an area lacking the high crater populations of the cratered terrain and thus younger (which the floor of Hellas is)

It was clear in 1969 that Mars had non-moon-like terrains, all involving younger surface processes than the cratered terrain so abunduntaly imaged represented, and it was clear that future missions were needed to make a complete picture and see how the "extra" pieces fit the puzzle.

Mars - Half the planet it used to be:

http://spaceweather.com/swpod2005/22dec05/warren1.jpg

I presume the dust storm that once threatened the rovers is gone as well? Or is Mars just too far away to see it clearly now?