APOD: Night Lights (2010 Nov 04)

[APOD Robot]

Night Lights

Explanation: Constellations of lights sprawl across this night scene, but they don't belong in the skies of planet Earth. Instead, the view looks down from the International Space Station as it passed over the United States along the northern Gulf Coast on October 29. A Russian Soyuz spacecraft is docked in the foreground. Behind its extended solar panels, some 360 kilometers below, are the recognizable city lights of New Orleans. Looking east along the coast to the top of the frame finds Mobile, Alabama while Houston city lights stand out to the west, toward the bottom. North (left) of New Orleans, a line of lights tracing central US highway I55 connect to Jackson, Mississippi and Memphis, Tennessee. Of course, the lights follow the population centers, but not everyone lives on planet Earth all the time these days. November 2nd marked the first decade of continuous human presence in space on board the International Space Station.

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[florid_snow]

I hate to be a downer, but all that light is completely wasted, lights are supposed to be for people on the ground, not space. I wonder what the process is, does it all come down to some city council person getting sold on some cheap light fixtures, "Oh there are no glare blockers, oh well, saves some money, order 10,000." About the image, does anyone know what the extra amber looking "limb" of the Earth is? It looks really weird, quite high altitude.

[Don Lund]

I hate to be a downer, but all that light is completely wasted,

Well, to be a little upper, I suppose that quite a bit of that light is reflected up from the ground.

OF

[florid_snow]

Oh I didn't think of that! Yeah, I often hear people say the Earth has an average albedo of .3. I'm just frustrated I have to use averted vision to see the Pleiades from where I live close to downtown.

[mexhunter]

I also think that governments should do more to reduce light pollution levels.
Technology exists to do so.
The photo is amazing.
Greetings
César

[toddnang]

I am curious what is the dark green band below the Earth's limb in the photo taken from the space station? It appears to be well above the level of the clouds, but I imagine it must be some atmospheric structure?

[León]

The image date is closely related to the previous day, as usual in Apod, the luminaries of the Necklace Nebula, on one hand, Mobile, Texas and New Orleans on the other.
Present in both the electricity

[neufer]

I am curious what is the dark green band below the Earth's limb in the photo taken from the space station? It appears to be well above the level of the clouds, but I imagine it must be some atmospheric structure?

Nightglow

Nightglow

---

<<Airglow (also called nightglow) is the very weak emission of light by a planetary atmosphere. In the case of Earth's atmosphere, this phenomenon causes the night sky to never be completely dark (even after the effects of starlight and diffused sunlight from the far side are removed).

The airglow phenomenon was first identified in 1868 by Swedish scientist Anders Ångström. Since then it has been studied in the laboratory, and various chemical reactions have been observed to emit electromagnetic energy as part of the process. Scientists have identified some of those processes which would be present in Earth's atmosphere, and astronomers have verified that such emissions are present.

Airglow is caused by various processes in the upper atmosphere, such as the recombination of ions which were photoionized by the sun during the day, luminescence caused by cosmic rays striking the upper atmosphere, and chemiluminescence caused mainly by oxygen and nitrogen reacting with hydroxyl ions at heights of a few hundred kilometers. It is not noticeable during the daytime because of the scattered light from the Sun.

Even at the best ground-based observatories, airglow limits the sensitivity of telescopes at visible wavelengths. Partly for this reason, space-based telescopes such as the Hubble Space Telescope can observe much fainter objects than current ground-based telescopes at visible wavelengths.

The airglow at night may be bright enough to be noticed by an observer, and is generally bluish in color. Although airglow emission is fairly uniform across the atmosphere, to an observer on the ground it appears brightest at about 10 degrees above the horizon, because the lower one looks the greater the depth of atmosphere one is looking through. Very low down, however, atmospheric extinction reduces the apparent brightness of the airglow.

One airglow mechanism is when an atom of nitrogen combines with an atom of oxygen to form a molecule of nitric oxide (NO). In the process a photon is emitted. This photon may have any of several different wavelengths characteristic of nitric oxide molecules. The free atoms are available for this process because molecules of nitrogen (N2) and oxygen (O2) are dissociated by solar energy in the upper reaches of the atmosphere, and may encounter each other to form NO. Other species that can create air glow in the atmosphere are Hydroxyl (OH), molecular Oxygen (O), and Sodium (Na)and Lithium (Li).>>

[Redbone]

Another great picture, thanks!

[orin stepanek]

I really enjoyed the video found in the links. http://www.nasa.gov/externalflash/expedition_10_years/
Worth watching!!! 8-)Click on video!

[Ewoki]

Hi everyone.

Any Idea what these lights on the ocean are? ships or drilling platforms or both and why so bright?

Greetings

[zbvhs]

It is amazing. Even flying over darkest Nevada at night you see lights scattered about. Dang humans are everywhere!

[Chris Peterson]

Any Idea what these lights on the ocean are? ships or drilling platforms or both and why so bright?

Those lights, plus most of the isolated lights on land, and many of the "stars" are nothing but noise. This image is extremely light limited, being only 1/4 second long. It was shot with the camera ISO at 51200, which is useful for seeing something under dark conditions, but produces very noisy images.

[rstevenson]

Any Idea what these lights on the ocean are? ships or drilling platforms or both and why so bright?

Chris is probably right about noise in the image. (Chris is always right ... isn't he?) But yes, there are ships and drilling rigs within the range of this image, and the rigs especially can be very bright.

Rob

[Chris Peterson]

But yes, there are ships and drilling rigs within the range of this image, and the rigs especially can be very bright.

The good light pollution images made from space always show oil rigs in the Gulf. In this image, you can approximately separate the noise from real light sources by examining it at full resolution. There is some motion blur, so the real light sources are slightly elongated. Noise is just a single pixel effect, so it shows up as fairly symmetrical spots. Noisy pixels will often look like a saturated color, as well, since each pixel lies under a color filter, and is therefore interpreted as a pure color.

There are definitely real lights visible in the ocean areas of this image.

[brgl]

Maybe the green lights

"well above the level of the clouds"

are some sort of reflection of LEDs coming from the Space Station on the lens ... The green looks as bright as the auroras above Norway and Alaska of the earlier APOD photos and somehow made me think of the Matrix codes ... I'm talking of the other lights in the right corner of the picture, not of the glowing of the Earth's atmosphere !

[biddie67]

Congratulations to the ISS and to all those humans that got it up there, kept it up there and have actually been able to live on it !!!

We are so used to having lights at night here on Earth - it's a real head trip to live out in the forest and experience true night when the local power grid craters every once in a while .....

[Sam]

There are definitely real lights visible in the ocean areas of this image.

And real stars, too! The Lyre and the Dolphin on the right [edit: sorry, other right], and Fomalhaut and perhaps even Alnair on the right, though that one's too far south for me to be familiar with. If I had the formatting skills of Neuendorffer I'd attach a picture of a dolphin leaping out of the water just like this one is leaping out of Texas.

Sam

[KerschbaumIfAVienna]

I like the Subject Distance of 2147483647.000 m in the EXIF header. Seems they lifted the ISS out to 5.6 times the distance to the moon...

[Chris Peterson]

I like the Subject Distance of 2147483647.000 m in the EXIF header. Seems they lifted the ISS out to 5.6 times the distance to the moon...

My EXIF viewer shows twice that: 4.29e9. Note that this is 2^32, which suggests that this field in the EXIF header is 32 bits, and when set to the maximum value is probably interpreted as infinity- which of course, does mean something a little different in a photographic context. The reason we are seeing different values probably has to do with how the top bit is interpreted; your software seems to be treating the value as signed, which means the distance is actually negative, but since that doesn't have a physical meaning, it doesn't display the minus sign.

[Chris Peterson]

And real stars, too! The Lyre and the Dolphin on the right, and Fomalhaut and perhaps even Alnair on the right, though that one's too far south for me to be familiar with.

Don't you mean "left"?

Vega is the bright star close to the Earth's limb, near the left edge. The five other bright stars of Lyra are seen below it and to its right, with beta Lyra (Sheliak) almost at the boundary of skyglow. Delphinius is at the center left, just above that ISS structure supporting the solar array. I'm not sure what's on the right- Piscis Austrinus, maybe?

[Robotronik]

I'm curious as to what that green halo around Earth is. Aurora? Light reflecting off the atmosphere?

[Robotronik]

Oh nevermind. I missed that post

[alter-ego]

And real stars, too! The Lyre and the Dolphin on the right, and Fomalhaut and perhaps even Alnair on the right, though that one's too far south for me to be familiar with.

Don't you mean "left"?

Vega is the bright star close to the Earth's limb, near the left edge. The five other bright stars of Lyra are seen below it and to its right, with beta Lyra (Sheliak) almost at the boundary of skyglow. Delphinius is at the center left, just above that ISS structure supporting the solar array. I'm not sure what's on the right- Piscis Austrinus, maybe?

I believe the constellations are Piscis Austrinus and Grus. Formalhaut is the brighter star on the right, and Beta Gru nearest the Earth's limb (Al Nair is behind the Earth's limb).

Close-up of right side of APOD photo
(click to enlarge)

[Ewoki]

But yes, there are ships and drilling rigs within the range of this image, and the rigs especially can be very bright.

The good light pollution images made from space always show oil rigs in the Gulf. Noise is just a single pixel effect, so it shows up as fairly symmetrical spots. Noisy pixels will often look like a saturated color, as well, since each pixel lies under a color filter, and is therefore interpreted as a pure color.

Thanks for the explanations Going up there and see where are the oil rigs and ships would be the sollution.
Another day.

The lights remember me at branching of neurons. really organic.