Can it affect seeing?

[alan potts]

Here is a question I have no answer to, I know it is not observing as such but do you think it has an affect on seeing?

I live in the centre of Bulgaria, few towns dark sky (no water) but at any one time I can see 5-7 aitcraft crossing the sky, all above 20,000 feet. Now if anyone in England lives on the main flight path to say Heathrow, most of this is low level but I am sure it has a part to play in the seeing we get if only from polution.

High level traffic leaves white lines across the sky which seems go at evening time, but do they. I would love to know how many plans go over in a day, it's over 200 I am sure.

Anyone got any thoughts as to if this has an effect on the quality of seeing?

Alan.

[jimmyjamjoejoe]

I would imagine it does, at least in the short term. I think runways need 60-90 secs between planes due to the vortex they leave.

I've seen videos of planes passing infront of peoples telescopes and the thermal currents are awful. I imagine they're shortlived, and for most of us not a problem. But living close to a major airport, the air would probably never settle in time before the next plane passed.

[VigdisVZ]

For planes on cruising altitude I don't see the contrails as that much of an issue for seeing, however if you're into AP, you will get white trails with red pearls on your subs

Living 4km from the largest airport in Sweden , its the light pollution thats the issue, not the planes turbulence by far.

[JB80]

Contrails can be a huge issue though, it depends on the atmospheric conditions as to how they form out but they have ruined many a night for me when they start to spread out and form a blanket of cloud.

[username]

If you have lots spreading out it might affect transparency more than seeing. If you can see them well (like when the Moon is out), how they spread out might out might be affected by the seeing (turbulent atmosphere dissipating the contrail quicker). That's just a hunch though, not based on anything concrete

[Peter Drew]

I'm under the flightpath into Manchester airport and high flyers from Heathrow. Turbulence is very noticeable but short lived, contrail residue certainly reduces transparency and I'm convinced it has a lot to do with the sky not being as dark as it used to be. By contrast, observing from Tenerife, even from sea level, is far better due to lack of similar pollution.

[LukeSkywatcher]

The best skies i can remember was back in April 2010 (???) when the Icelandic volcano erupted. There wasn't a single plane in the sky for days. No contrails to spread out and ruin the sky. Even during the day, the sky was bluer then i had ever seen.

[cotterless45]

Contrails are horrible. Sometimes, if there's no movement in the upper air they just spread out. Other times they fade quickly. Worst one was when I was looking at the Moon and a jet flew under the fov. Thought my eyes had gone funny with all the wiggly waggly air ( technical term).

We live on the East Midlands airport corridor, have found aviation fuel across the mirror.

Nick.

[alan potts]

The best skies i can remember was back in April 2010 (???) when the Icelandic volcano erupted. There wasn't a single plane in the sky for days. No contrails to spread out and ruin the sky. Even during the day, the sky was bluer then i had ever seen.

I hear what you say Luke but I didn't notice any change and most of the planes disappeared from the sky if not all of them. I had the scopes out almost every night then. I started astronomy in 1972 and I am sure that the sky was darker then. I was in Hull only a couple of months back and I couldn't believe how bad it was from the City.

Alan.

[LukeSkywatcher]

Contrails are horrible. Sometimes, if there's no movement in the upper air they just spread out. Other times they fade quickly. Worst one was when I was looking at the Moon and a jet flew under the fov. Thought my eyes had gone funny with all the wiggly waggly air ( technical term).

We live on the East Midlands airport corridor, have found aviation fuel across the mirror.

Nick.

True. I have seen many in the sky that simply drift away in whatever direction the winds are blowing. Others tend to spread like the plague and form a lovely (not) layer of cloud across the whole sky.

My auntie lives under the flight path of Gatwick and the amount of contrails in the sky above her house is unreal, not to mention the noise. She doesnt notice the noise, but its deafening to me when i visit. Every 30 seconds or so...............another plane takes off and passes overhead pretty low down.

[LukeSkywatcher]

I hear what you say Luke but I didn't notice any change and most of the planes disappeared from the sky if not all of them. I had the scopes out almost every night then. I started astronomy in 1972 and I am sure that the sky was darker then. I was in Hull only a couple of months back and I couldn't believe how bad it was from the City.

Alan.

You didnt notice any difference in the sky quality when the planes were grounded over europe?

Seriously? you didnt notice any difference?. Maybe, the difference was more noticable during the day when us astronomer types are not out observing. The sky was bluer than blue. When the planes started flying again, the sky returned to its usual milky blueish white.