The planet Mars

This image was taken on 19 April 2014, just 11 days after Mars was at opposition. A number of surface features are visible as well as the polar caps (the north cap is at upper left) and cloud formations at the equator.

The dark triangular feature at right is Syrtis Major, while Sinus Sabaeus and Sinus Meridianii are the horizontal dark markings stretching away left from its base.

The technique for planetary imaging of this kind is to take high frame-rate video (~100 fps) for about 30 seconds through each colour filter, then use software such as AutoStakkert to sort the individual frames by quality, selecting the best say 200 to be stacked so that the signal to noise ratio is enhanced. The resulting colour masters are then combined to produce a colour image.

Even with such techniques, planetary imaging from the UK is challenging to say the least. Apart from the weather, our skies often suffer from poor ‘seeing’,  and often the planets do not climb very high into the sky. This image was taken with Mars at an altitude of 30° above the horizon, from where its light has to pass through twice as much atmostphere as it would if shining overhead. Thanks to a short period of steady seeing, this image turned out surprisingly sharp – not the usual result!

Meade 14″ LX200ACF, Flea3 U3-13S2M camera. Stack of 150 frames taken through each of LRGB filters.