Details on Mars

Matt and I set up my 16" modified Lightbridge to look at Mars on Saturday night near San Antonio.

I was using my 10mm Radian eyepiece at 180X.

With no filter, Mars appeared as a rather large disk with no features that I could see. It was a big red version of Uranus which I had seen many times over the summer. However we ran my set of filters to see what might emerge.

With a yellow filter, I was able to see a bright lenticular shape on the north end of the planet. This was the first time I had ever seen planetary detail on Mars. Just like with double star observing, North was determined by seeing which way the planet fell out of the eyepiece field upon waiting a minute. The direction that the planet moved was West. North was therefore 90 degrees counter clockwise from that direction.

An orange filter did not add much more detail than the yellow provided.

A deep red filter was useless for me. All detail seemed to have disappeared including the ice cap.

With a green filter, not only was the ice cap visible, there were some smoky smudges on the disk. I especially thought I saw more of this toward the west and a little north of the Martian equator.

A Lumicon Deep Sky filter showed little detail, though the ice cap could be seen.

A Lumicon UHC filter showed both the icecap and almost as much smoky detail as the green filter.

The scope sat outside all evening before we observed at about 930 PM. However, there was still considerable thermal activity on the mirror observed in a star test. I was able to see the polar ice cap about half the time I was looking at the disc. The smoky areas, with the green filter, seemed to be present about 1/3 of the time.

It was interesting trying to filter out my own eye floaters from the image my brain was trying to interpret. The disc is just small enough that a floater which passes over the disc calls attention to itself as though it might be a planetary detail.

Rick

Ruminations on Astro Sketching

I think one of my central problems with drawing is that I want to draw
more detail than what I see.

When I sketch a tree, or a landscape, I have learned by experience that
the secret to making it represent what I really saw is to include less
detail than a photograph would.

I think I need to start thinking about astro sketching the same way.
Maybe I should - like John E - go back to sketching a constellation.
Accurately putting each star that I can see in its place, but not
worrying about getting every star into the drawing.

Instead, my impatience too often leads to unfortunate results when I get
tired of drawing what I see and suddenly create a mass of close dots to
represent an area of cloudiness. In the end, it is a sense of rush that
leads me to ruin what I have put time into drawing.