Mars & Diemos (or Maybe Not!!!)

[niallk]

Set up the 15" and let it cool from 9pm to 12:30pm, and saw rewarding views of Mars - it was a beautiful night, but spent over 1hr just on Mars and then packed up: no DSOs - work tomorrow!!

Lots of detail to be seen - seeing was a little variable, but some good moments.  Also very dewy!

Scrawling over  http://www.nightskies.net/mars/mars.html#, the features in purple were clearly visible, nice polar cap - smaller than I remember from my last view of Mars ~3 months ago; i thought the green regions showed lighter relative to the purple ones, and i did not discern the finger like dark blobs in the Aurorae Sinus.

The other noticeable feature was a teeny pinprick - Diemos.  No matter how i tried, no Phobos, it had passed behind Mars, and if it had come out again, was too close to the planet/glare - especially as I breathed out on the EP from time to time! 😆  Diemos matched Stellarium well, but Sky Safari seemed off (?!).  Chuffed to finally see Diemos ;).

EDIT:

Hmmmm.... not convinced now that I saw Diemos- could have been a background star, trying to match up again from memory.   Nothing for it but to try again another night! 😁

Edited September 21, 2020 by niallk

[niallk]

This, from: https://www.cloudynights.com/topic/730268-mars-september-10-animation/#entry10520962 is pretty much what I was seeing with a 6E giving ~330x (if I close 1 eye, and hold at arm's length).  I hope the author of the post doesn't mind me pasting here - it's a nice video showing rotation over several hours!

Edited September 21, 2020 by niallk

[RobertI]

Nice report, must have looked good through the 15”. I saw an identical aspect through my 4” the other day - the ‘notch’ between Margaritifer Sinus and Sinus Meridiani was clearly visible, but not much else! Would love to see Mars through a big scope. 

[niallk]

Yeah I suspect I was seeing this mag 10.6 star rather than Diemos, which was a similar distance on the opposite side of the planet, and not shown in my Stellarium app. Think I got over excited, and didn't flip L-R & up/down correctly 😅

Edited September 21, 2020 by niallk

[John]

Interesting report

I've tried a couple of times to see Deimos and Phobos when observing Mars with my 12 inch dob.

I've spotted a few "suspects" but on checking I discounted them as being a bit to far from the planet, wrong orientation etc.

I tend to use Cartes du Ciel to check positions of planetary moons as this has been accurate for me with other planetary moons.

While these two tiny moons look as if they should, from their magnitudes, be possible with a decent aperture scope I suspect the reality is that they are a lot harder and their elongations from Mars need to be optimal to give us a chance to glimpse them.

I'm going to keep at it though and I'm sure you will

I've found these links which are useful:

https://www.observing.skyhound.com/shallow_sky/mars_moons.html

https://astronomynow.com/2018/07/30/find-martian-moons-phobos-and-deimos-at-the-red-planets-closest-approach/

Looks like Phobos will never be more than one planetary diameter away from the Martian disk, which will make that one very challenging !

[rob_r]

46 minutes ago, niallk said:

Yeah I suspect I was seeing this mag 10.6 star rather than Diemos, which was a similar distance on the opposite side of the planet, and not shown in my Stellarium app. Think I got over excited, and didn't flip L-R & up/down correctly 😅

I think I made the same mistake last night too. I got my first sight of Mars too and spotted a bright dot some way off Mars, I thought it could be one of the moon's but seemed too bright. I could see it by averting my eye on to the planet through my 127 Mak and it was on completely the wrong axis anyway as I was using a diagonal.