Observation of Mars on the 1st March 2025

For the last week and a half we have had some very settled mild weather dominated by high pressure to the south of us. This has enabled me to leave my HEQ-5 telescope mount outside covered up with a plastic bag and to use it whenever I was able. Ten days ago on the 1st March I had another go at drawing Mars. This planet is now retreating from us and its diameter has shrunk from 13.6 arc seconds on the 2nd of February to 10.9 arc seconds on the 1st of March. As a consequence it is getting harder to make out the detail. Here is the page out of my notebook:-

At about eight in the evening Mars was quite high above the horizon and roughly due south. There was quite a bit of thin cloud/haze about but the seeing was pretty good and the image steady. I was using my Orion OMC140 Maksutov Cassegrain again with a 9mm orthoscopic eyepiece that gives a magnification of about 222x. I began with a pre-printed template and drew in the details using coloured pencils. The above image has washed out the original colours, so I have just reproduced the drawing below where I have adjusted the saturation and colour temperature:-

 

It seemed to me that the northern polar cap has either shrunk in size since my last observation or the cap has tilted away from us. To my eyes the southern cap area looked less dark than before and I actually thought frozen white parts were visible but this may not be the case. At this time the central-meridian longitude that was pointing towards us was 220 degrees. According to the Sky & Telescope Mars Profiler the dark area to the south is likely to be Mare Cimmerium. 

I have been in touch with the BAA Mars Section director Richard McKim to see if my drawings are of any use to the BAA but it seems I need to be able to resolve more detail before any science can be made from them. To this end I should really be using my x2 barlow lens as well to get the magnification up to 444x but I think I had been reluctant to do this because the image appears so much dimmer. The other alternative is to wait until another opposition in 2 years time when Mars will once again be a bit bigger (and brighter). Still, I have made a start! He did like the colours I was using which he said did match what he expected. I may try and do a disc drawing of Jupiter as further practice.

 All text and images © Duncan Hale-Sutton 2025