måndag 8 augusti 2011

Correcting the Neumayer parts of the 8.7.11 video

For the lat/long and other facts about Neumayer see my Facts about Neumayer post.

Auroras are often ocurring near the poles and can last very long : "Undulating ribbons of light may shimmer in the sky for hours"

At 24:25 it's mentioned that there's something very bright in the left 
corner of the image, causing the auroras. That is absolutely right -
it is the sun, and as we know the Aurora Borealis/Australis is caused by
charged particles hitting the earths magnetic field.
Now if you go to the Horizon Views at YourSky and enter 2011-08-06 07:20:00 the sun isn't up!
That's because a couple of things :
  • it's the sensitive night vision view of the webcam we're seeing so the amount of light is highly exaggerated
  • sunrise is when the disk touches the horizon and with the low inclination of the sun at the poles in winter, the sun stays just below for a long time. 
At 10:30 UTC it's up - which brings us to the rising of the crescent moon at 24:45 in the video :  If you enter the Neumayer values at http://aom.giss.nasa.gov/moonloc.html you see that the moon rises at about 7:00
Since the sun is to the left of the moon, and the reflection of the sun rays
is what's causing the moon to shine, the left part of the moon should be lit; just as in the images.

One thing missed in the video is that at 25:40 you can see them sending off one of the weather/ozon/whatnot-balloons.

At 26:20 there's a strange bright object in the sky. Well as you can see in the comparison between the (slightly enhanced) webcam shot and what YourSky says it's clear that it's Fomalhaut - according to Wiki "one of the brightest stars in the sky"

The reason the Radar Dome shadow hasn't been seen lately (as mentioned at 27:00) is that the moon has just been a sliver and not able to produce shadows. If you go to YourSky, enter 21:40 and change the Azimuth to NW instead of SE you're in essence looking at what's behind the webcam - and there's the moon. And as we've seen it's now going on half moon so there is enough light to produce shadows. In the coming weeks they will be even more pronounced.

At 28:45 there seems to be some misunderstanding of how lens flares work.
There is a strong lightsource (since it's the night vision it doesn't have to bee that bright. And at 29:50 we do see it in day vision) on the "beacon" and the reflection it makes in the lens causes the flare. There's nothing up and off to the right causing anything.

At 29:30 that's Sirius and to the right above we see the "triangular ship" aka dogs-ass we saw in the 8.1.11 blog. I'll leave it up to the reader to go to YourSky and prove it.

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