AndyHogg

Posted by T16GER in the Muppet forum, but I believe it should be here, amazing photograph

http://antwrp.gsfc.nasa.gov/apod/ima...s_dmsp_big.jpg

Andy

mega_stream

Amazing
Thats a good site, some fantastic pictures

mega_stream

What a job eh?

ozzy

Superb pics. Will the last to leave, please turn out the lights

andy oakes

Scoobysport downpipe is standard on this model sir!!

UkLegacyT

they are REAL photo's.
stunning mate, will have a further look on that site when ive got more time, cheers.

ian

catflap

That is simply amazing

i can see wales from there

hay i can even see the m4 corridor, its fantastic

No i cant see my house

StiScoobySteve

Photoshop!

Since when is the entire earth blacked out at the same time?

letdown

And it would appear that not a single person lives in Greenland !!

Still looks ace though !

Dazzler

Shocking to see how one continent is lit up like a beacon (America)and another is nearly in total darkness (Africa).

catflap

It must have some sort of edating, there is never a total blckness on the earth, possibley an eclips? very good though

CRAIGFIN

I reckon it must have done using time lapse technology over a day.

Craig

Squizz

I flew back to england at 1am on Sunday morning... You could pretty much see the entire country from 37,000 feet thanks to a clear night and all the lights.

Stunning...

The pilots must be so blase' about such a thing though.

Dan B

Ah, a chance to show off I have a degree in astronomy and am now doing a PhD in astrophysics..... prepare for the high horse.

The picture posted above has not been photoshopped, but taken though a "fish eye" lens. Hence Earth has been rounded somewhat.

The Earth's surface is never in complete darkness as it is a sphere lit from only one direct (the Sun). The only object to effectively eclipse the earth is the moon, but as the moon and sun are so far away the area of the earth surface to experience darkness is minute.

The surface of the earth at night photo has (probably - not too sure), been taken by a mapping satellite that has been put into an orbit which takes it only though the dark side of the earth (it would also have has to have waited until the surface is unobscured by cloud (unless taken at a wavelength which travels through cloud).

I LIKE MY JOB

zax

Excellent image, looks great when used with xplanet. A real, living, daytime/night time earth complete with accurate cloud cover on your desktop!

http://xplanet.sourceforge.net

StiScoobySteve

Ok then, i'm happy with that explaination.
Thanks

mark_h

I saw that earth lights pic when it was released back in Nov 2000; I remember reading all about it then. It's funny how it's only in the last month or two that it's started appearing everywhere I look.

yoza

Look carfully in the Liverpool region,those two brightest lights you can see are my Morrettes.So the picture is genuine,infact I think I remember his flash gun going off.
Sorry for lowering the tone Yoza
ps anyone know how to pop a bonnet on a MY01 washers run out and owner handbook not in scouse!

carl

Blimey, Dan! PhDs in Astrophysics must have got easier recently

(snips out GCSE description of Earth/Sun orbital dynamics)

My prediction -- photograph is from a polar-orbiting satellite, probably something like a 1 deg wide 'swath' taken on each path (which would look like a sinewave on the projection shown) with something like a quarter of a degree overlap on each pass.

Then there's some serious post-processing gone on (on the ground) to stitch the bits together, followed by mapping onto a Mercator projection of the planet (which is what this is). This image is not representative of what the satellite saw, as it would be looking straight down (even over the poles).

A check of the reference on the picture reveals it's actually a composite from a series of satellites from the Defense Meteorological Satellites Program which are in near polar (i=99 deg) sun-synchronous orbits at around 800km, which means their orbital planes precess by around a degree a day so that they track the motion of the Earth around the sun -- i.e. throughout the year they see each individual spot on the surface in roughly the same sort of illumination. To make a satellite in permanent darkness you'd either have to arrange for its orbital plane to precess by 360 degrees a day (I can't imagine how you'd do that) or put it at the Sun-Earth L2 point (which is a long way away)

matrix

Dan B

Putting it at L2 would work, but thats x4 earth-moon distances (or something like that). Not thats thats too far to map the surface, just cost too much. Maybe NGST will do it as past of commissioning...

carl

L2 is about .01 AU, so 4 lunar orbit radii is a pretty good guess

ozzy

Don't think it's been doctored in Photoshop. It was in the news last year. You can get more info from here Earth from space

At least there's still places to go to get some piece and quiet

Stefan

[Edited by ozzy - 3/8/2002 10:12:43 AM]