The weekend brought some lovely clear skies. I’ve made the effort once before to get up and catch Saturn just before dawn. As the year goes on Saturn will be rising earlier and earlier in the evening, until at opposition in mid April it should be visible most of the night, however, for now I still have to get up early, at least to allow Saturn the time to rise above the skyglow. This meant setting the alarm for 4.30am on a morning where the thermometer was just touching -8 degrees!
Saturn is currently positioned in Virgo, just north east of the bright Spica, one of the brighter stars in the sky. Just four days before, Saturn started moving backwards across the sky, in ‘retrograde’ motion, a visual effect that happens as Earth catches it up in orbit. If you’re into astrology rather than astronomy, and a Virgo, this will have some special meaning for you I think!
My main objective this morning was to try a get a photo on the webcam. The webcam is proving tricky, as getting the correct exposure, contrast, white balance and gain is very trial and error for me at the moment. Add to the mix the rippling effect from an unsteady atmosphere and you never quite know whether the session has been a success or not.
In this case, I am very very pleased with the result. I shot 5 mins of video, and using the PC took about 200 of the best quality still frames and stacked them in software. This helps reduce the effect of ‘seeing’ (the rippling atmosphere) as well as adding detail to the image. Saturn is shown north pole up, with rings tilted towards Earth (current tilt about 15 degrees). The Cassini ring division is clearly seen as a black line towards the outer edge of the ring system. A cloud band can just about be seen north of the equator. Where the rings pass behind the planet on the eastern side a dark ‘gap’ can be seen just before they go behind the planet. I think this is where Saturn is casting its shadow over the rings – amazing.
