Anyhow, after much swearing and stubbing of toes, the beast was safely within its harness and it was time to go. Luckily Saturn, my target for the night, was easy to find. I must say that he was truly a sight; bright, full of colour and detail, a little jewel in the still-blue velvet of twilight. Though I knew my aim for the evening was a picture, I could never quite tear myself from the eyepiece. Using ever more power I was able to coax out ever more detail from this heavenly delight.
There is something about Saturn that is not felt with the other planets. Maybe it's the majestic rings or the teasing hints of detail which lie tantalizingly just beyond the reach of the eye, but something about that crowned globe makes one's pulse slow, and one's breath catch in the throat. Whilst he hangs silently before you in the night, the mind spontaneously conjures tales of deep space voyages and raging star-battles. For a time, you're whisked away on an intergalactic sojourn of the imagination until suddenly, with a knock of the eyepiece and a wobble of the scene, you're brought reflectively back to Earth.
Well, after about half an hour of peering through the huge telescope, I decided that it was time to obtain some proof of my evenings work, and so I popped in my trusty QHY5v guiding camera, and....
...nothing; a blank black screen. Maybe I'd nudged the target from the field of view? No. Was the camera working? Yes. Most perplexing. I struggled with these two questions for maybe ten minutes, before finally realising I'd not set the exposure on the camera. At a distance of about 790 million miles at that time, I was going to need a bit more sensitivity!
After many a tweak of the settings and a readjustment of the focus, I was ready to try an image, or rather, a series of images. With planetary imaging, the stability of the atmosphere, or 'seeing' as it is known, becomes key. Throughout the day and night, there is a great deal of temperature change, wind and other turbulence within our atmosphere, and at the high magnifications necessary for planetary imaging and observation, this becomes highly apparent. Through the eyepiece, it is manifested as something resembling watching a penny at the bottom of a fountain pool; the flickering, dancing image ever perturbed by the rippling of the water, making it nigh on impossible to obtain a clear visage. So too with the atmosphere - how are we to know when to press the shutter on the camera, when ninety nine times out of a hundred the view will be obscured?
To get around this problem, we take a video of the target, rather than a single image. This video can then be cut up into all its individual frames and the compromised images (the large majority) discarded. We are then left with a smaller number of images where the atmosphere has cleared, which can be stacked and aligned to make a final image of our target.
Well, that's the theory anyway, but after my first attempt last night I can assure you it's not that simple! I'm not sure what I'm doing wrong yet, whether it be something in the cameras settings, the focus (usually is with me!), the quality of the seeing or an unpleasant combination of all of the above, but there's plainly still a very long way to go. Still, I do now have my first planetary image, and here is is. Saturn, with its majestic rings, thousands of miles in diameter yet gossamer thin, it's wind speeds of up to 1100 miles per hour and its zoo of curious and dynamic moons, here represented by a misshapen blotch on your screens. For that I apologise, but hopefully better is to come:
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| Saturn (ish): 26/27th May 2013 |
