Cassiopeia Observatory - Report - Imaging Mars and Saturn; Critters

Imaging Mars and Saturn; Critters

Posted: 26 June 2014

On the previous report about my night at Oracle State Park I mentioned the Oak Fire burning in the mountains 25 miles east of Oracle. Today, from the highway west of Oracle, the smoke from the fire rising from behind the nearby hill was very visible:

1936 MST: Mars, 222X. North Polar Cap nicely visible. Did some iPhone 5s imaging of Mars. At 444X without a filter, Mars was overexposed. Added one of the filters from the Variable Polarizing Set to reduce brightness. This is a stack of 1720 slo-mo frames (120 fps; 15 sec), 444X + filter:

Mars is getting too small now capture much detail, but the North Polar Cap is still visible in images.

Then began setting up for the ISS pass. It was not as good a pass as the last two ISS passes but still worth imaging. Mounted the D7000 DSLR at prime focus + 2X PowerMate. Focused using Saturn and locked the telescope focus. Checked the finderscope alignment; OK. 1954 MST: now ready for the ISS pass to begin (2010 MST). 2000 MST: breezes have gone, calm now. The ISS would initially appear through a tree to the northwest of the observatory and against a still bright sky. When the pass started, it took me several minutes before I located the ISS in the sky. The initial telescope pointing was way off. I didn't catch up with the ISS until mid-pass and by the time I did, tracking was pretty bad. When the pass was completed I slewed to Saturn and discovered that somehow the focus had slipped slightly. During post-processing, what few frames of the HD video that had the ISS showed it was out-of-focus. Rats. There are no more good ISS passes for awhile.

Refocused on Saturn and did some D7000 DSLR HD video recordings at PF + 2X PowerMate. This is a stack of 387 frames (24 fps, 15 sec), 1/60sec, ISO 4000:

Some movement on the observatory floor caught my attention. Looks like dinnertime!

Next, I did some iPhone 5s imaging of Saturn at 444X. Here's a comparison of two stacked images showing the effects that longer video recordings have on the result. The left image is 1128 slo-mo frames (10 seconds). The right image is 123 frames (1 second).

The shorter video shows clearer details (atmosphere cloud bands and Cassini Division) than the longer recording. That's due to atmospheric distortion blurring out more frames in the longer recording. Since I don't remove bad frames from the video before stacking, the shorter recording results in a better image.

I did some Saturn observing, 444X. Four moons were visible in the FOV with Saturn: Rhea, Dione, Titan, and Tethys. At 222X and 83X, the moon Iapetus was visible well away from the planet.

Since I had been at Oracle State Park for a long time the previous night and I had a full day of errands afterward, I was tired and decided to close the observatory for the night.

I created a short video of the excellent ISS pass on 22 June 2014 using selected frames from the HD video recording I made with the D7000 DSLR.

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