Unexpected Mars, 02 Feb

[brianb]

A somewhat surprising mostly clear evening last night allowed me to image Mars for the first time for several weeks. Though transparency was good (between patches of drifting low cloud) the seeing was poor, with considerable boiling. However, with only a light wind and much lighter than average dewing, I had to have a go:

2010 Feb 02, 2308 UT. CM 351 degrees. Celestron CPC1100, Meade series 5000 x3 tele-extender (f/30), Astronomik type 2c colour seperation & Planet Pro 742 filters, Imaging Source DMK 21 camera.

Top row: LRGB composite using IR (contrast reduced) as luminance; LRGB composite using red channel as luminance; RGB composite; simulation (Starry Night Pro v6.21).

Bottom row: infra red, red, green & blue channels. (900/6000, 600/3000, 600/3000 & 900/3000 frames)

f/30 was too much for the conditions; I intended to make another sequence with a shorter focal length but the seeing deteriorated to awful shortly after this sequence was completed, an hour or so later the cloud closed in completely, terminating the night's activities.

The dust band over the polar cap can be seen, most clearly in the green image, and both morning and evening haze / cloud can be seen - all along the NE limb and just north of the equator at the W.

[russ]

Brian,

Those are superb and wonderfully detailed.

[beamish]

A wonderful collection !! Well done Brian.

[michael.h.f.wilkinson]

Great stuff!

[Clayton]

Very nice images, and i like the informative presentation as well.

[rwg]

What never ceases to amaze me about pictures like these is that if I pull down an old astronomy book from the shelves (in this case Patrick Moore's 'Guide to the Planets' - 1971 ed), the plates in the book of Mars, Jupiter etc taken with the 200" Palomar scope don't match up to this sort of webcam image taken with 8"/10"/12" scopes in someone's back garden...

wow...

Robin

[Jupiter Martin]

Thats amazingly clear detailed images

[brianb]

Thanks guys.

I know the exact Palomar plates you mean ... just shows the value of the "lucky imaging" technique, plus the sensitivity of modern CCD sensors compared with the old photographic emulsions. I remember trying to image Saturn with film around 1970, exposures were several seconds rather than a fraction of a second so seeing tended to play havoc & withn only a single shot the noise was horrible.

In fairness to the Palomar people, those few planetary images were made for publicity rather than as part of a serious observing programme, and they probably got planetary time on nights which weren't suitable for faint object spectroscopy i.e. nights with substandard seeing. Lick Observatory made some excellent lunar images with the 120" back in the 50s which are very nearly equal to the best modern ground based amateur images, certainly much better than our individual webcam frames.

[sheri_barri]

Very good shots! Loads of details!!

Cheers,

Sheri

[Lensman]

Hi Brian,

Very nice images, lots of detail there.