Mars Observation 28 August 2018 - Best of the season

[MarsG76]

Date: 28th August 2018 @ 22:50 – 00:40AEST

Sky Condition: Great 9.5/10

Wind Speed km/h: 200hPa:40 850hPa:15

Equipment: NexStar 8SE, CGEM, Skyris 618C, IS DMK21au618, 16" Sony VAIO, Contrast Booster, Neodymium, Meade Light Blue, Celestron Nō8 Pale Yellow and Meade Yellow, Baader IRPass685nm Filter.

When I was at work, I had a quick look at the sky condition for the following few nights as I had those nights off work. It’s forecast that the seeing and stillness of the atmosphere is going to be very still tonight but very poor for the next few nights, so I had to observe and image Mars tonight or miss out on the opportunity of good seeing.

 

Mars: I started on Mars with capturing 10 x 2950 frame videos of Mars in colour and IR using the Skyris and the IS21au618 CCDs before moving onto observing. Since Mars is still very bright, I was able to capture at 80fps/60fps and collect the data within 15 minutes before spending the rest of the session at the eyepiece.

 

Almost immediately as I put my eye onto the eye piece, I could see that Mars was very still and sharp. The disc was very big and the southern polar cap was so bright that it was almost glowing. The shape of Mars was obviously past the full phase and one of the edges, left side from the polar cap in the eyepiece, was more flattened, Mars is definitely on it way away from us.

Looking at Mars at magnifications of 185X and 290X, both of the views had their benefits. Initially the view was better with the 11mm Nagler but as the night progressed the atmosphere obviously improved slightly and the view became better at 290X since the definition was the same as at 185X but on a noticeably bigger disc.

The dark marking were concentrated along the terminator and toward the lit edge of the Martian disc, but there was visible fanning out of the markings toward the south pole, the polar cap. Occasionally there was a short splintered bit on the marking that ran toward the terminator side of Mars, and was about 1/3rd of the length of the martian disc. It was very sharply separated from the pinky part that is north of it. This sharp separation is my proof that I have had a very still and transparent sky tonight.

The northern side of Mars looked more featureless, no dark markings but the southern and lit side edge of the disc had a distinctly brighter spot which would have been about 1/5th of the size of the martian disc. This spot is a visibly much brighter area than any of the pink-orange areas around the darker markings.

When I had a look at Mars with the 11mm Nagler and with only the Neodymium and Contast Booster filters, the disc was much brighter, as expected, with the polar cap being even brighter, glowing and throwing itself into view but the darker markings seemed to be becoming lost within the glare. Markings were still visible but not with as much ease or with as much detail as viewing when filtered down. Even though the detail on Mars was subdued, the brighter view in the eyepiece revealed what might possibly be a martian moon, Phobos or Deimos!! I certainly still have my doubts that it’s a moon for two reasons but I am hopeful and there was a point of light visible near Mars.

The reasons that create doubt to the point of light being a martian moon are that its too bright. It is easily visible with direct vision and because Mars’ moons are very small they are apparently (and reported by other observers) very faint and easily lost with in Mars’ glare. The second reason to doubt it to be Mars’ moon is the fact that it is low south and far away from Mars’ equatorial orbital plane, about 8 Mars disc sizes away from Mars and about 30° toward the terminator side of Mars when using above Mars’ south polar cap as the zero degree mark.

I have noticed the point of light when returning to the filtered 290X magnification view, so whether it is a moon or not it doesn’t matter since the view through the eyepiece tonight is absolutely stunning.

Pushing the scope to 370X was slightly too high, as the dark marking were harder to see, and not as defined as at 290X but the polar cap was still obvious all the time along with occasional dark marking coming into view on the big Mars disc.

Before packing up I did insert the X-Cel 5mm eyepiece, and as expected the view at 406X was softer but as I was about to pull my eye off the eyepiece, I had a slight glimpse of surface markings pop into view so I spent a bit more time at this power. The marking never became as obvious and clear cut as at 290X but they were visible, along with the bright polar cap and the different shading of the pinky orange hues throughout the disc.

Using the whole stack of the 5 filters revealed the dark marking much more easily than with just the use of the Neodymium and Contrast Booster filters, the view was noticeably dimmer but the details were much more obvious. The best magnification when comparing stillness, sharpness and ease of detail visible through the eyepiece and past the eye floaters was at 290X using the 7mm LV.

The view tonight was great…

The image is the closest I could simulate the actual view by flipping and blurring my image from this night to represent what I saw.

…the views of Mars which I have had tonight were definitely the best I have had, not only, during this Mars season but overall to date. I’m glad that I did not take the lazy way out and opened up the observatory  after work and after my gym workout tonight. I could have given the seeing 10/10 but there is always room for improvement and the atmosphere was not as still as it can potentially get. My only regrets are that Saturn and Jupiter were not visible anymore and that I did not have the mirrors collimated on the SW14 since I have no doubt that those sights would have been amazing.

 

Update: During processing the Mars data, WinJupos showed Phobos and Deimos to be in completely different positions comparing to the position of the point of light, so the point of light was not a Martian moon but just a background star.

 

[mikeDnight]

Fantastic! A very realistic visual impression and a credit to you.

[Dave1]

Brilliant right up, very detailed.