Mars Observation (Augst 21, 2005)

I made a pair of observation of Mars on August 21, 2005 (06:00 (IL/W35) and 06:40 U.T. (W38)) which showed interesting detail over the martian surface and atmosphere. The South Polar Cap (SPC) was prominent. The region between Mare Cimmerium and Syrtis Major was complex (alternating light and dark patches). Hellas was extremely bright (9/10) and prominent. I welcome any comments on my observations.

Date (U.T.): August 21, 2005
CM: 231.9 (left), 241.6 (right)
Ls 273.0 (Early Northern Winter/Southern Summer)
De -14.3, Dia. 13.0", p 0.86
Instrument: 9-inch (23-cm) F/13.5 Maksutov-Cassegrain
Magnification: 248x and 344x
Filters (Wratten): 35 (magenta) and 38 (blue)
Seeing (1-10): 6-7, Antoniadi (I-V): III-II
Transparency (1-6): 4

Notes:
Left Image (06:00 U.T., IL/W35): The South Polar Cap (SPC) appeared brilliant (10/10) and prominent. No detail was noted within the SPC. Mare Chronium (3-4/10) was visible north and surrounding the SPC. Simois (4-5/10) was visible extending between the southern border of Mare Cimmerium and Mare Chronium, bisecting Phaethontis (7/10) and Electris (7/10). Eridania (7/10) was visible as well. Mare Cimmerium (3-4/10) was visibly extending from the south-preceding limb and following the CM. A bright (7/10), circular albedo feature (Atalantes Depresio?) was noted over the southern border of Mare Cimmerium adjacent to Hesperia (7-8/10). The diffuse (5/10) albedo feature "Valhalla" was noted to be north and parallel to Mare Cimmerium. Mare Tyrrhenum (3-4/10) and Syrtis Minor (3/10) were prominent following the CM. The region appeared "speckled" during brief moments of steady seeing. Mare Hadriacum (3/10) was noted along the preceding border of Hellas (9/10). Syrtis Major (3-4/10) was noted as a "wedge" along the following limb. Iapygia Viridis (3/10) was visible towards the following limb south of Syrtis Major. Aeolis, Aethiopis, and Aetheria were bright (7/10) with little detail visible. Cerberus (5/10) was visible as a thin wedge south of the extremely bright (9/10) North Polar Hood (NPH). Libya (7-8/10) appeared to be partially obscured by haze. The Hyblaeus Extension (?, 3-/4/10) was visibly partially obscured by the NPH. A thin, extremely bright (9/10) morning limb haze (MLH) was visible. A more prominent (9/10) evening limb haze (ELH) was visible as well.

Right Image (06:40 U.T., W38): The South Polar Cap (SPC) was brilliant (10/10). Hellas was extremely bright (9/10) and appeared to have a thin, bright to very bright (7-8/10) projection extending from it's preceding border then across Eridania and Electris and connecting to the extremely bright MLH (possible mixture of ground fog and water-ice clouds?). A very bright to extremely bright (8-9/10) cloud was visibly projecting over Elysium. The North Polar Hood (NPH) was extremely bright (9/10) as well. Mare Chronium, Mare Cimmerium, Mare Tyrrhenum, Syrtis Minor, and Syrtis Major were diffusely visible using the blue (W38) filter.

The best of luck in your own imaging and observations of the red planet.

Regards,
Carlos E. Hernandez

Attached Image:

As always, Carlos, a fine report. (Hey, you're not the Martian for nothing! )

I realize you're not one to yack too much about this scope versus that scope -- you've been observing far too long to get mired in that discussion, so I'm going to try and make my question quite simple and "unloaded."

Are you still as pleased and happy with your Maksutov now, as you were when you first got it? Sounds like Mike did a great job.

Cheers & best wishes.
-Dan

Carlos:

I always enjoy reading your reports while looking at the sketch you made... it really helps me reinforce the more obscure albedo features and gives me something to strive for next time I look. If I keep reading your reports, I'll soon be able to pick out more Martian features on a map than Earth ones! :^)

Bruce.

Bruce and Dan,

Thank you for your kind compliments on my latest observation of Mars. I was impressed with the amount of detail visible over this region of the planet. I expect that we will pick out even more detail in the future as the planet becomes larger in apparent diameter.

I do not mind discussing instruments to be used for lunar and planetary observing as long as the discussion is focused and respectful. The first thing I must state is the "There is no perfect instrument for the Moon and planets." The classical refractor (including Apo's) and long-focus (>f/6-8) Newtonian are considered by many to be "perfect" for use on the Moon and planets, but they too have their disadvantages. The classical refractor is an unobstructed optical system and therefore provides maximum contrast on the Moon and planets. I have had wonderful observing experiences using well made refractors on the Moon and planets in the past. The problem with this design is the expense for apertures greater than 4 inches (10 cm) and the mount required for the long tube. A shorter tube Apo refractor is a solution to the mounting problem but these are very expensive! The long-focus Newtonian (>f/6-8) is another high resolution design for the Moon and planets. This design allows for a smaller diagonal (e.g. central obstruction, <20%) as well as an achromatic image. The problem with this design is similar to the refractor in the stable mount required for it to be used at high magnification. These instruments may be close to perfect but still have their problems as noted. Many amateurs therefore resort to the classical Newtonian (1/4 wave) and on a stable mount this can be a powerful instrument for use on the Moon and planets. The classical Cassegrain reflector (>f/20) is another possibility for use on the Moon and planets. The problem here is the difficulty in producing acceptable primary and secondary for this long-focus design and maintaining collimation. The Schmidt-Cassegrain reflector is also useful for the Moon and planets as evident by the excellent observations posted on this forum using this design. The problem with this design is the size of the secondary (~33-35%) and the variability of surface accuracy by SCT manufacturers. I too own a quality SCT (vintage Celestron 8") which I used for many years. If well figured and collimated they can make good planetary instruments.

This brings me to my current design the Maksutov-Cassegrain which I am fond of. The more I use my instrument for the Moon and planets the more that it impresses me. I am not calling this design perfect as it can become expensive in the larger apertures (as refractors) and the meniscus which holds the secondary can take some time to cool off in temperate climates. Living is South Florida my variation in temperature is not too great and my cooling period is brief (usually < 1 hour). The tube is compact and easy to maneuver. I find the images produced by this design to be the sharpest and of high contrast of many designs that I have used in the past. This may be a personal preference but I am very happy with my instrument.

The best lunar and planetary instrument is the one that the amateur uses regularly on the Moon and planets in order to gain experience in observing these beautiful objects!

Regards,
Carlos

Carlos,

Thanks for sharing your beautiful Mars images.

Could you advise a beginner how to get started drawing Mars in hopes of immulating some of the technique you have mastered?

Specifically, are there texts, instructions, manuals to help instruct a beginner in learning necessary skills and knowledge.

Also, maybe a few tips on pitfalls to avoid.

I am sure any advise would be greatly appreciated by many.

Thanks,

Robert