Observation by Martin Lewis: Mars RGB and IR 31st July 2018
Uploaded by
Martin Lewis
Observer
Martin Lewis
Observed
2018 Jul 31 - 22:05
Uploaded
2018 Aug 03 - 20:32
Objects
Mars
Equipment
- 444mm Dobsonian
- ASI174MM for IR
- 742nm for IR
- ASI174MC for RGB
Location
St Albans
Target name
Mars
Title
Mars RGB and IR 31st July 2018
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Comments
Mars on the night of closest approach to Earth on 31st July during a night of relatively calm seeing.
I have waited a while to image Mars at a decent hour- unlike others I am not able to image in the early hours of the morning due to an early rise for work. This image was from my upper patio- here I can image the planets before culmination but not on the meridian or post meridian due to neighbours trees. An earlier session on Saturn was encouraging and so I left the scope set up in eager anticipation of my first views of Mars of this apparition just after opposition and at 24arcsec.
Seeing was actually better on Mars than Saturn which was surprising as the elevation was only 11° an altitude at which my atmospheric dispersion corrector was under-correcting, even it's at max setting with an extra 2deg prism added in. The altitude was so low that I had to temporarily remove a wooden fence panel that was partly blocking the end of the scope!
The view shows the subdued albedo features in the visual after the recent global dust storm but a much clearer view in the IR where Sinus Meridiani and Margaritifer Sinus are seen either side of the meridian. Colour balancing Mars was very difficult due to the big brightness difference between pole and globe and the big attenuation of the blue by the atmosphere.
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