Full Moon next to Venus???? (APOD 23 Apr 2008)

[watch24]

Translated: Indeed, the stars are visible!!!!!!!!!!!! The sky at about 3000m is magnificent. At 4000 to 5000 m it more difficult, due to the lack of oxygen in your blood. But in all these cases the stars are visible at these high altitudes. Atmospheric scintillation /dispersion has nothing to do with vision in that matter, that is absolutely ridiculous.

So that settles it...the first-hand comment I was waiting for. I guess I was right and wrong at the same time: The vision is degraded (remember, my question never was 'are they visible?'), but reportedly has nothing to do with atmospheric dispersion. Actually the notion of oxygen deprivation making vision difficult was also touted by a geologist here in my office, but it's always good to get a second opinion.

My feelings aren't hurt...my ideas have been called 'ridiculous' by frenchmen before.

Thanks for asking![/u]

[watch24]

The sky at about 3000m is magnificent. At 4000 to 5000 m it more difficult, due to the lack of oxygen in your blood.

This may explain why I've been more impressed with dark skies near sea level than when camping at 3000m. Someone who's used to higher altitudes and in really good shape, like Serge Brunier, probably doesn't need as much oxygen to function well, but the average couch potato may start to have trouble at lower than 4000m--maybe even in the reduced-oxygen environment of a commercial jetliner cabin. Anyway, it explains my original question in this thread about why my friend said they had to take the tour group below 9000' on Mauna Kea to view the night sky....whew!

[henk21cm]

This may explain why I've been more impressed with dark skies near sea level than when camping at 3000m.

There are two items that influence vision itself: the amount of oxygen and the amount of sugar in the blood. With little oxygen you will suffer from "tunnel vision". When the amount of sugar in the blood is raised, the eye will focuss slightly different. There is one main item that influences the interpretation of vision: toxins, like alcohol, LSD or other drugs. "Impression" is a psychological factor, which i count as interpretation. Similarly, the sky in a forrest is less impressive than the sky, as visible on a wide open plain, like the APOD of 2008-04-16.

Someone who's used to higher altitudes and in really good shape, like Serge Brunier, probably doesn't need as much oxygen to function well,

What SergeBrunier meant with "plus difficile" is that the feeling of enjoying the stars is more difficult due to the depreviation of oxygen. That was lost in my translation. Nonetheless stars are visible by the naked eye, even at 5000m altitude, according to Serge.

If we are lucky, he will gather some new amazing pictures. When i contacted him, he was due to fly to the Atacama dessert within a few hours and he wrote that he had even better equipment on this trip. I hope we are in for a new treat.

IMHO that has wrapped up the loose ends of this thread.

[Sputnick]

This is a little late, but I camped at Treeline at Jasper National Park, Alberta, Canada, 30 years ago and the stars looked like a mirror image of Jasper village below. It was quite an experience. So .. to get to Jasper Avenue, turn left at Andromeda.

[watch24]

This is a little late, but I camped at Treeline at Jasper National Park, Alberta, Canada, 30 years ago and the stars looked like a mirror image of Jasper village below. It was quite an experience. So .. to get to Jasper Avenue, turn left at Andromeda.

The first time I really took notice of the night sky was in the BWCAW about 10 years ago (Boundary Waters Canoe Area Wilderness--Canada/Minnesota border). I wanted to see the Andromeda galaxy, so a buddy and I took off accross a big lake at 1 A.M. to get away from the tree line. The lake was like glass and reflected the sky perfectly. I was sitting in the bow, so unless I looked down, I couldn't see the bow wave or the front of the canoe. I couldn't see the other side of the lake either. It was the coolest experience I'd ever had--like drifting through the galaxy without a space suit. It actually gave me a bad case of vertigo, and I had to stabilize myself to keep from falling out. You gotta try it sometime!!!

I've been hooked on astronomy ever since.

[Sputnick]

Watch - Your space canoe would have been quite a trip. I had the vertigo experience in a canoe on perfectly calm water at about 2 p.m. on a beautiful summer day .. clouds and blue sky reflecting into the mirror of the river which was about a mile wide, with me in the centre .. talk about sudden and total disorientation thinking I was up instead of down .. I guess that's why airplane pilots sometimes dive into the ground or sea.

The universe's 'planes' are interesting mirrors- example, an exploding star sending out mirror plumes.

[dalessio]

I am an astronomer and I hope I can help...

The fact that the resolution of the eye is of the order of arcminutes simply means that a point source (a star is a point source for all practical purposes) will appear to be about 4' in size. The atmosphere only makes it harder to see stars, not better. No matter where we are all of the light of a star will be spread across these 4'. The atmosphere makes this substantially worse, and absorbs some of the light. This spreads the image across a larger area >4' and makes the star fainter to our eyes. If we go to higher altitudes we get a purer image. The issue that stars are tough to see at high altitudes >8000 feet is because your eyes are not getting enough oxygen.
However, in a plane, or in the space station the oxygen supply is fine and the sky should appear very clear. We are then completely limited by only our eyes optics and no degrading atmospheric effects. I have never been able to see stars out of a plane window, but those are usually double paned and very dirty (plus don't forget you are looking through air traveling 500 mph, which is terrible optically). From the space station the sky is probably incredible. However, you will not see this from a picture or video camera. These devices are not meant for recording faint objects. Go ahead and try to take a picture of a star from earth with a normal shutter speed, or take a video with stars in it. You will not see any stars.
Remember Hubble is just a camera in space!

So the summary is... Less atmosphere, stars appear smaller, which means they will be brighter and easier to see, as long as you are getting enough oxygen.