Pictures of Earth From Mars

11223 writes "Mars Global Surveyor has snapped a picture of Earth from its Mars orbit. This picture, the first of its kind, shows Earth, the Moon, and Jupiter. Earth is visible as a half disc exposing North and South America; apparently the Moon had to be "processed" into the picture."

Comments

Another Pic

[BurritoWarrior]

From National Geographic:

Pics.

Makes you realize how big Jupiter is...

[mooman]

If you go to the space.com website, they show you that in that shot, Jupiter is about 7 times farther away from the viewpoint, but it still appears dramatically larger than earth in the full image.

We all know Jupiter is big but this rare chance to phyicially see it compared to our own planet is kinda profound...

or maybe I just need to get out more.

Re:Makes you realize how big Jupiter is...

[djtack]

If you go to the space.com website, they show you that in that shot, Jupiter is about 7 times farther away from the viewpoint, but it still appears dramatically larger than earth in the full image.

This is partly due to the long focal length of the lens. It distorts perspective, the same way a photographer can make the moon apear much larger by taking the picture with a long telephoto, at a distance from the subject.

But no doubt, it was inspiring to see Earth and Jupiter in the same frame together.

Re:Better format?

[robsimmon]

Actually, the raw (black and white, not contrast adjusted) image is saved as a GIF - and it's still pretty big 'cause there's some invisible noise in the black.

In any case, JPEG does LZW (or similar) compression as a final step, so a JPEG would also have been very small if the noise was removed.

Re:Images look funny

[fiiz]

Hehe,

thanks, thanks, thanks.
I was actually wondering, and couldn't be bothered to do the calculation myself.
It's nice to see something that's not a wild uninformed guess every now and then on /.

Keep it up, and, guys, *mod parent up.* ;-p
from a thankful astrophysicist.

Re:Mirror

[Migrant Programmer]

Thanks for the mirror, it was mighty fast =)

I cropped up a wallpaperable version of the image that you can get here (9821 byte PNG). It looks nice on a black desktop.. sure puts things in perspective!

Not the first far-earth pictures

[TFloore]

NASA has been doing cool pictures from far away for a while. Two that are worth looking at:

Solar System Family Portrait
This one is nice, but earth is really only about 4 pixels, so you can't see all that much detail. :) This is a Voyager 1 picture taken in 1980, I think.

Saturn in shadow
This is a nice shot of Saturn by the Galileo probe, taken with about half the planet in shadown. Read the write-up there, it's kind of cool.

Smooth

[_ph1ux_]

I read someplace that the earth - on scale is more perfectly smooth than a machined steel ball bearing. If you were to scale the nicest ball bearing you could find to the size of the earth it would have pits and ridges, mountains and valleys far larger than anything on earth.

Earth looks pretty smooth from these distances

Hmmmm, interesting

[JWSmythe]

So, I decided I couldn't see details well enough, so here in our office, we opened up the pic in GIMP.. If you adjust "Brightness" and "Contrast" all the way up (127 on each), illuminated objects really stand out..

I'm looking at something I don't understand though.. What we're looking at is the full shapes of the objects, plus refraction from the atmosphere, right?

The "Earth" is a vertically aligned rectangle with bright bars of red, green, blue, with splatters of yellow and aqua. There's a grey box coming off the left side.

The "moon" is a white dot with a black and white checkerboard pattern going to it's right.

Jupiter now appears as a larger white blob, with only a little bit of blue at the bottom, but instead of a diffused pattern, or even a finite box around it, there are three boxes, stretching from the top, left and a smaller from te right.

The right-most moon only has a tall rectangle with a similiar checkerboard pattern to the Earth's moon.

The far left moon has a lesser pattern than the Earth's moon, but it's still aparent.

The 2nd from the left moon has a distinctly different pattern.

What we're finding most pecular is that there are absolutely no stars aparent in this picture.

From the Earth, Mars looks like a bright star, in a field of stars.. Shouldn't a view from the same distance (Mars -> Earth = Earth -> Mars) have a similiar sky view? At least the larger stars should jump out at us in this picture. At least we should be seeing more stars by cranking the contrast all the way up... I'm not expecting like spectacular starfield views or anything, but I'd expect at least one..

This honestly looks like a serious photo-shop job. Someone took a black background, dropped on a few very small images, with Jupiter being the only one with distinct patterns.

It's seriously missing stars.. Bringing the contrast up a bit should at least show *SOMETHING* in there.. Looking at a night's sky from Earth, even with the city lights, if you can see Mars, you can see huge starfields.. I don't think I've ever seen Mars, and not seen any stars...

I wanna see a real picture..At least that'd be cool. :)

Re:Hmmmm, interesting

[SiliconEntity]

In my experience, looking at Jupiter with a telescope, it is not uncommon to see stars nearby that are somewhat fainter than Jupiter's moons. It's surprising to me, given the large area of the photograph, that no stars appear bright enough to show up, since Jupiter's moons are quite bright looking in the picture.

Here's one example I found with google, someone's photo of Jupiter and Venus. It's a little similar, you see Jupiter in the lower left with 3 moons, and Venus in the upper right. And there are a fair sprinkling of stars about.

Now the difference is that this is a longer exposure, you can see that Jupiter and Venus are way overexposed. That's necessary to see the Jupiter moons.

I think the Mars picture has been tweaked quite a bit. You should not see that much detail on Jupiter if the moons were that bright. So they turned down Jupiter, they turned up the moons, and they didn't turn up the stars, so we don't see them.

Re:Fake fake fake

[KewlPC]

It's also the movie that Duke Nukem 3D stole the line "I have come here to chew bubblegum and kick ass. And I'm all out of bubblegum." from.

Interesting effect with contrast turned up

[Jeffv323]

I just turned up the contrast on the JPEG for kicks, and what interests me, is the fact that the shadow side of the earth becomes visible. Maybe it could be due to refraction of light in the atmosphere or actual city lights (could it?) but I don't know enough about optics and light to answer that.

Here's the original.
Here's my version.

Also, somebody said something about the original grayscale GIF right from the camera being available. I couldn't find it but if anybody else has it, please post a link.

-- Jeff