Thermal slide/lunar/planetary

[jetstream]

I was wondering if anyone else has explored the concept of the thermal slide with regards to local thermal management?

In conversation with a local astronomer 300km away the conversation swung over to local thermal management. By chance we both do similar things. Hes an imager (and vg) and Im a visual observer.

Basically  you observe in an area (higher) that allows the cooling evening air to "slide" down the hill taking ground heat with it, resulting in better local seeing conditions. I discovered this when clearing an area of our property and brought a scope up. The difference is significant.  The preferred base for me is sand- it reflects heat in the day and cools fast at night.

This is one of the ways used to squeeze out very high mag on solar system objects. I find this interesting.

 

[markse68]

I usually observe from the top of a 3 storey building- does that count? Surrounded by terrible light pollution though so that likely cancels out any benefit. And the building shakes when heavy trucks trundle down the main arterial road right next to it...

Mark

[jetstream]

1 minute ago, markse68 said:

does that count?

No.

 

[Gonariu]

15 minutes ago, markse68 said:

Di solito osservo dall'alto di un edificio di 3 piani: conta? Circondato da un terribile inquinamento luminoso, quindi probabilmente annulla qualsiasi vantaggio. E l'edificio trema quando i camion pesanti percorrono l'arteria principale proprio lì accanto...

Segno

At least the moon, sun and planets should be within your reach; the important thing is to do what you can.

[markse68]

I've had some fantastic views of the planets from up there so there may be something in it, and it's very convenient which is the main thing

Mark

[jetstream]

2 hours ago, markse68 said:

I've had some fantastic views of the planets from up there so there may be something in it, and it's very convenient which is the main thing

Mark

All joking aside you might be experiencing the effect when observing up there, congrats for getting some fine views!

[mikeDnight]

I'm situated on a north east facing ridge with the top of the ridge and a small woodland blocking my western horizon. There's a river a couple of hundred yards below me and my planetary seeing is generally very good. Deep sky not so good, or at least not as good as it used to be. Perhaps the cooling principle applies in my case, or may be it's just my location that often has a light mist and steady air that aids planetary viewing? I do know that my late friend, who lived quite high up on a hill at the edge of town and higher than me to the south, had terrible seeing, but good transparency, but may be it was the heat from the town itself that played havoc with his site? 

[jetstream]

7 minutes ago, mikeDnight said:

but may be it was the heat from the town itself that played havoc with his site? 

For sure Mike, in my case I get thermals off the lake and ice believe it or not. Up on the ridge things are much better and when I quote very high mag its up there.

You sound like you have a great spot to observe from and yes I think the slide deal applies to you. Your seeing reflects your excellent observing & skills.

[VNA]

Hello, if I go higher I will have more trees in the way!
So lower is better for my views, besides, no fun to carry a scope up a hill on a steep muddy trail! ;- )

[Froeng]

On 04/03/2023 at 21:55, markse68 said:

I usually observe from the top of a 3 storey building- does that count? Surrounded by terrible light pollution though so that likely cancels out any benefit. And the building shakes when heavy trucks trundle down the main arterial road right next to it...

Mark

It does count! I do the same and anything that get’s you away from the ground seems to provide a seeing benefit. I think it is said the ground turbulence stops almost completely about 20m up. There is a guy in the middle of Paris who’s posted some astonishing videos of Jupiter on youtube. He took these from his high rise balcony. He did use a Mewlon 300 though…

[jetstream]

2 hours ago, Froeng said:

I do the same and anything that get’s you away from the ground seems to provide a seeing benefit

Thermal slides do work and can have many forms. My 15" goes from about 450x on Jupiter to over 600x on the hill. Detail at lower mags is so impressive under good seeing and local seeing controlled.

I was curious if members were aware of its benefits and hoped to bring it to "light" to help others get better views.

[Froeng]

2 hours ago, Froeng said:

It does count! I do the same and anything that get’s you away from the ground seems to provide a seeing benefit. I think it is said the ground turbulence stops almost completely about 20m up. There is a guy in the middle of Paris who’s posted some astonishing videos of Jupiter on youtube. He took these from his high rise balcony. He did use a Mewlon 300 though…

I think it was this one: