Observing Session in the Fog!

[David Smith]

Had an unexpected gap in the clouds late yesterday afternoon as I was driving home. Had quite a bit to do when I got home but was pleasantly surprised when I looked out at 22:00 to find it was still clear. It was beginning to fog over but was still very clear from about 35 degrees upwards and my experience is that nights when it is going to be foggy have very good seeing so I got out quick.

Jupiter was fantastic in the Dob, some of the clearest views I have had in months. Even at over 200x the image was rock steady with detail all across the disk. Particularly noticeable was the detail in the equatorial zone which I always seem to struggle with. Last night though the zone was full of whispy cloud formations and "bright" pale / white areas.

Session only lasted an hour as the fog built up quite quickly but while it lasted it was fantastic. Fingers crossed for more nights like that.

[VigdisVZ]

Nice to hear about nights like these. Thanks for sharing.

[stuy]

Had an unexpected gap in the clouds late yesterday afternoon as I was driving home. Had quite a bit to do when I got home but was pleasantly surprised when I looked out at 22:00 to find it was still clear. It was beginning to fog over but was still very clear from about 35 degrees upwards and my experience is that nights when it is going to be foggy have very good seeing so I got out quick.

Jupiter was fantastic in the Dob, some of the clearest views I have had in months. Even at over 200x the image was rock steady with detail all across the disk. Particularly noticeable was the detail in the equatorial zone which I always seem to struggle with. Last night though the zone was full of whispy cloud formations and "bright" pale / white areas.

Session only lasted an hour as the fog built up quite quickly but while it lasted it was fantastic. Fingers crossed for more nights like that.

i have been observing the planets for 30 yrs and always look for thin foggy conditions or mist, these can produce the finest planets images! was out myself withthe 10" mak tack sharp@ 380x in bino veiwer a sight to behold was going to do some images but i was enjoying the veiw so much!!! we dont get good seeing here very often!! stuy

[Double Kick Drum]

i have been observing the planets for 30 yrs and always look for thin foggy conditions or mist, these can produce the finest planets images! was out myself withthe 10" mak tack sharp@ 380x in bino veiwer a sight to behold was going to do some images but i was enjoying the veiw so much!!! we dont get good seeing here very often!! stuy

It almost goes against instinct. I had the best view of Jupiter a few days back and will now look for a little moisture in the air to view it in the future.

[bus_ter]

Don't these conditions also equate to extreme dewing issues?!

[David Smith]

I did not have an issue with dew but then I was using the Dob with the light / dew shield. Might be a different story if your using a frac / mak /sct maybe?

[JamesF]

The fog was so thick here that night that visibility was down to almost nothing. If I'd have gone out I'd have struggled to find my way back to the door

James

[David Smith]

The fog was so thick here that night that visibility was down to almost nothing. If I'd have gone out I'd have struggled to find my way back to the door

James

There are limits to how far this theory carries as James has discovered!

[JamesF]

I was at one point struck by the irony that not that many days previously I'd been looking at objects so far away that even light takes hundreds of years to reach us, but that night I couldn't even see to the end of the garden...

James

[bish]

I had my best view in years a couple of weeks ago, infact my best view of any planet. The good thing with planets is that crystal clear skies aren't the best, and you can observe them through cloud when nothing else is visible.

P.S I'm a vikings fan!

[JamesF]

I do struggle to see a scientific justification for crystal clear skies not being the best for observing planets, I have to admit. Intuitively I'd have thought that you'd need steady, clear skies to achieve decent (not necessarily massive) levels of magnification. Certainly my best views of Jupiter have been when the sky was beautifully clear, but that did also coincide with the first time I'd seen it using my 10" dob and 5mm Nagler.

James

[jimmyjamjoejoe]

I do struggle to see a scientific justification for crystal clear skies not being the best for observing planets, I have to admit. Intuitively I'd have thought that you'd need steady, clear skies to achieve decent (not necessarily massive) levels of magnification. Certainly my best views of Jupiter have been when the sky was beautifully clear, but that did also coincide with the first time I'd seen it using my 10" dob and 5mm Nagler.

James

Generally high, thin clouds bring good seeing with them. Ontop of that, when viewing with a larger scope i've found the added light grasp can somewhat glare out finer detail, thin cloud can cut that down, i've found an nd filter helps too.

Of course, you CAN have crystal clear skies AND good seeing, but that's a pretty rare occurence.

I dont know the meteorological causes behind it, maybe the process of condensation removes heat from the air or something. It's often said that patches between lower, regular clouds offer good seeing too.

[David Smith]

Agree with this, some of my best views of Mars / Jupiter / Saturn have actually come when I have had thin clouds over head. I distinctly remember a session looking at Mars and then discussing on here how the cloud seemed to improve the view.

Has anyone tried emulating this effect using an ND filter? The only ND I have is my Moon filter and this is too strong.

P.S I'm a vikings fan!

[jimmyjamjoejoe]

I have, but only with jupiter so far and it helped me. Not sure which filter i have but it's not very strong, maybe nd96? Rings a bell... similar to a very light pair of sunglasses.