Mars Opposition of 2020-2021
September 16. 2020. The smoke from the fires on the West Coast have reached New Jersey. The effect was like a light overcast with some reddened light getting through.
September 15, 2020. Last night we had the unusual conditions of light smoke overhead, coming all the way
from the west coast. Not nearly as bad as it was in the midwest where my friend Ralph Taggart was only able to image Mars in the NIR. In addition, there was enough overcast or fog
that I was unable to image Jupiter around 8 pm.
September 13, 2020. Seeing was quite good this morning when I took 17 one minute long videos of Mars with the ASI183MC camera at the f/14 focus of the Schupmann. These videos were processed in AS!3 with deconvolutive sharpening turned on. The resulting images were converted into the animated GIF shown below. They were also derotated and stacked in WinJUPOS and then sharpend a bit in Registax6. This image, with annotation, is shown above. Note that Olympus Mons is directly on the terminator. A contrast enhanced clip is also shown by the annotated image with grid showing the sunlit western slopes at sunset and the shadowed eastern slopes. Looks like a little bump, but is actually the tallest volcano in the solar system.
September 12, 2020. Seeing was pretty awful last night when Jupiter was observable and transparency was marginal. I got three videos, but the best processing only gave a big smudge with the NEB and SEB barely recognizable. Waste of time.
September 8, 2020. Good seeing this morning! Maybe 4/5 rating. I took 16 one minute videos of Mars at 432fps with the ASI183MC at the f/14 focus of the 7.25" Schupmann. I processed them with Autostakkert!3, aligning and stacking the best 8% of the 25945 frames in each video and then derotated and stacked the resulting images in WinJUPOS and finally sharpened and histogram adjusted the final stack which is shown above. The overlay grid on the right is courtesy WinJUPOS. Longitudes may be estimated from this grid which is 10°x10°. The central meridian is 241.5° East Longitude. Add 10° for each grid mark to the right, subtract to the left. The grid helps considerably in identifying surface markings. Labels are a mix of traditional, pre-spaceflight maps prepared by visual observers and modern NASA maps. We know there are no seas (Mare) on Mars, but NASA has no names for some prominent albedo features that do not relate to topographic features on the planet. Mare Chronium is just part of an extended Cimmeria Terra now even though it appears as a separate region based on its albedo (brightness). The animated GIF below was prepared from the 16 images using GIMP.
A slightly better result was obtained using 3% of the frames rather than 2%,
September 7, 2020. The high altitude of Mars continues to help out with the seeing. Although only predicted to be average, the seeing was much better than I am used to getting from Jupiter or Saturn under average conditions. I took 13 one minute videos with the ASI183MC at the f/14 focus of the little Schupmann, processed in Autostakkert!3, with the deconvolution sharpening turned on. I adjusted color balance and levels in Registax6 and rejected two of the images because some of the good frames got too close to the tiny ROI I had defined of 128x130 pixels. Maybe a bit too tight. Still, I got 432 fps and nearly 26,000 frames per video with a shutter of 2 ms. I derotated and stacked 11 of the images, each of which was a stack of only 2% of the frames in the video. This is pushing my luck in lucky imaging. Easy to do when you get so many frames in only one minute of video. After minor sharpening in Registax6 I got the result below. An image with grid, courtesy of WinJUPOS is included to help identify features. Each grid unit is 10°x10°. Note the small dark blob on the projection extending down (North) from Terra Cimmeria. That tiny blob is Gale Crater where Curiosity rover is tooling around learning things. Note also the very slight bluish haze over Syrtis Major. This is high level clouds, often more pronounced than this. There is also clouds extending south from the North polar cap where it is still probably snowing. It is still late winter there.
September 5. 2020. The sky did not look very promising this morning at 2 AM, variable haze and thin overcast and a well past full gibbous moon lighting it all up. Mars was shining brightly though, so I woke up my night assistant Chewie and we went back to open up the observatory and got busy with the Schupmann and the ASI183MC. Seeing was a bit above average, 3/5 or so and Mars was bright enough so that I could use an exposure of only 2 ms. I used an auto-histogram setting of 50% to deal with the variable transparency and took a set of 15 videos of one minute duration between 06:26 and 06:40 UT and achieved a frame rate of 375 fps and collected 22516 frames per video. I processed them in Autostakkert!3, keeping only the best 2% of the frames, sharpened with wavelets in Registax6 and then derotated them all to the common central meridian of 256° east longitude, stacked and sharpened lightly again to give the result shown below. Labels for albedo features are a mix of traditional and NASA names.
August 31, 2020.
Seeing was quite good when I got up at 2 AM to image Mars. I took 15 videos between 0620 and 0635 UT and worked them up
using Autostakkert3 to align and stack the best 3% of the 21720 frames in each of the 60 sec videos with 1.5x drizzling selected to give better sampling. These images were sharpened with
wavelets in Registax6 and then all 15 images were derotated and stacked in WinJUPOS to give the annotated image shown below.
August 24, 2020.
August 11, 2020. I got up in the wee hours this morning and captured 11, one minute long, videos of Mars using the ASI183MC at the f/14 focus of the 7.25” Schupmann. Seeing was below average but usable. My shutter was only 2 ms and I used a tiny ROI of only 128x128 pixels. This gave a frame rate of 437 fps and allowed the capture of 26,230 frames in each of the one minute videos. The best 5% of the frames of each video were aligned and stacke in Autostakkert3 and sharpened in Registax 6 then all 11 images were derotated and stacked in WinJUPOS and finally sharpened slightly in Registax. The annotated result is shown below. It is evident that a lot of dust got blown around back in 2018 when the global dust storm happened. The dark albedo feature Mare Sirenum and surrounding region looks different from my images from previous oppositions and the BAA maps. Will try to verify the changes as Mars gets closer. There are a couple of light spots near the terminator which I thought might be the sunlit western slopes of a couple of the Tharsis ridge volcanoes lit up by the setting sun, but the coordinates aren’t quite right. An animated GIF was also prepared from the 11 images and is attached.
Above is an image made with only 2% of the frames of one of the videos, but with less sharpening in Registax. Less of the edge artifact, but the albedo features are less visible. You win some, and you lose some...
July 27, 2020.
June 20, 2020. After Jupiter had vanished behind a tree and when I had finished with Saturn, I noticed Mars peeping above the trees to the southeast, well up in the sky. Got several 90 second videos of it, my first this opposition. Even though Mars is still quite small, a lot of detail (and no sandstorm) is showing up. Nice bright south polar cap, Hellas is bright and not obscured by dust or clouds. After derotating and stacking the 5 images, more detail emerged, in spite of the fact that Mars is now only 10.24 arc seconds across. The central meridian of the images is at 298.4 degrees and we are looking at a point 23.8 degrees south of the equator. Chasma Australe, an ice free region extending almost to the pole is visible as a dark wedge extending into the polar cap. The dark albedo feature is Syrtis Major near the terminator on the east. Hellas is prominent and neither covered with dust as it was early in the season nor white clouds. The annotated image of Mars is the first attachment.