Last night two days before opposition, Mars was 22.5 arc sec in size, just slightly smaller than at closest approach five days ago. Our orbits are not exactly circular so the time off opposition (with the Earth right between Mars and the Sun) and closest approach are a few days apart.
I captured 156GB of data over four hours for this animation, 2020-10-11 04:20-08:20 UT. Syrtis Major and Hellas are prominent. The best 10% of each video was used (about 1500 of 15000 video frames for each image). A Questar telescope 1350/89 mm with a Dakin 2x Barlow lens was used with a ZWO ASI224MC planetary video camera. Mars was high in the sky with fair transparency and fair to good seeing. I didn't use the ADC or any filters.
Camera exposure was 12.45 ms at a gain of 165 (unity gain is 135). Plate scale was 0.28 arc sec / pixel. Capture rate was 80 fps. Capture and processing on a MacBook with SER format data. Captured with FireCapture and lucky image stacking (1.5x drizzle) in AutoStakkert! 3. Final exposure, crop and rendering as a GIF animation was in Photoshop. Final rendering 0.132 arc sec per pixel.
Content created: 2020-10-11
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