APOD: Mosaic: Welcome to Planet Earth (2010 Jul 13)

[APOD Robot]

Mosaic: Welcome to Planet Earth

Explanation: Welcome to Planet Earth, the third planet from a star named the Sun. The Earth is shaped like a sphere and composed mostly of rock. Over 70 percent of the Earth's surface is water. The planet has a relatively thin atmosphere composed mostly of nitrogen and oxygen. This picture of Earth, dubbed Blue Marble, was taken from Apollo 17 in 1972 and features Africa and Antarctica. It is thought to be one of the most widely distributed photographs of any kind. Here, the world famous image has been recast as a spectacular photomosaic using over 5,000 archived images of Earth and space. With its abundance of liquid water, Earth supports a large variety of life forms, including potentially intelligent species such as dolphins and humans. Please enjoy your stay on Planet Earth.

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[bystander]

Very nice, Rob! I'm impressed. Congratulations!

[mexhunter]

Hi Rob:
An authentic and beautiful crafts.
Congratulations!
Regards
Cesar

[nhaenni]

Very nice picture, thanks!

Reading the last two sentences makes me think on what a beautiful jewel we live on ... and that we should watch out when the dolphins depart the Planet Earth.

Best regards
Nicolas

[zzwerzy]

Yes, beautiful. But Africa and Antarctica - not so much.

[owlice]

Congratulations, Rob! I was delighted to see this as an APOD; yay!!!

[Ann]

Yes, congratulations, Rob! This is a very fine picture. I think you yourself said about it that you particularly liked the background blackness of space, which is made up of hundreds of images of small galaxies seen against the blackness of space... the realism of this is very attractive, isn't it?

Ann

[Ann]

Is it really true, though, that the Earth is mostly made of rock? I thought it was mostly made of iron and nickel. Perhaps iron and nickel make up most of the Earth's mass, but rock makes up most of the Earth's volume?

Ann

[rstevenson]

Thank you all for the kind comments. Did you notice Albert Einstein overseeing the whole thing from his perch just east of the south-eastern tip of the Arabian peninsula? Al does like to drop in once in a while just to check things out.

Rob

[rstevenson]

Is it really true, though, that the Earth is mostly made of rock? I thought it was mostly made of iron and nickel. Perhaps iron and nickel make up most of the Earth's mass, but rock makes up most of the Earth's volume?

By coincidence, I was paying attention in class last week.

Counting the atmosphere, the earth is about 50% oxygen with half the remainder being silicon. Then there's a bunch including (in descending order) aluminum, iron, calcium, sodium, potassium and magnesium. At that point we're below 1% for each of the rest of the elements.

I find it interesting that we think of the earth as having lots of nickel in its core, and there certainly seems to be plenty in the upper crust for mining, but it doesn't even make the list in my textbook. An on-line reference tells me it makes up only 0.018% of the total. Iron, by the way, is number four in the list with less than 5%.

Of course "rock" is made up of lots of things including silicon and oxygen and carbon and ... . And since a whole lot of rock contains those top two elements and many others near the top of the list, I suspect that yes, the earth can be said to be mostly rock, though a good deal of it would be molten.

Is there a geologist in the house?

Rob

[biddie67]

rstevenson - what a spectacular effect!! Good work!!

I'm sure the dolphins have already considered the negative impacts of that other species ....

[DavidS]

Beautiful job..... and the keywords in the description "potentially intelligent" hit the nail on the head.

[orin stepanek]

I liked the story about the Sun; Sol. It was both humerus and educational. I always love a picture of the Earth.

named the Sun.

Nice job Rob!

[Paulmac]

"Potentially intelligent species" - dolphins and humans? Are you joking? Humans are, dolphins are not, cute as they may be.

[guit.art]

What a fantastic piece of work! Science and art in perfect harmony.

[Henning Makholm]

Is it really true, though, that the Earth is mostly made of rock? I thought it was mostly made of iron and nickel. Perhaps iron and nickel make up most of the Earth's mass, but rock makes up most of the Earth's volume?

By coincidence, I was paying attention in class last week. :shock:

Counting the atmosphere, the earth is about 50% oxygen with half the remainder being silicon. Then there's a bunch including (in descending order) aluminum, iron, calcium, sodium, potassium and magnesium. At that point we're below 1% for each of the rest of the elements.

That sounds like the figures Wikipedia gives for the crust alone. For the planet as a whole, the iron figure is significantly higher (at 32%, opposed to about 5% in the crust).

Of course, it is considerably easier to run assays on crust samples than to do whole-planet estimates...

[DCStone]

"Potentially intelligent species" - dolphins and humans? Are you joking? Humans are, dolphins are not, cute as they may be.

After all, all they do is eat, swim, and play, while we fight terrorists, attempt to clean up massive oil spills, and argue about whether man-made global warming is real or not... Ok, so Douglas Adams was right.

Actually, defining intelligence is very complicated, and I'm far from convinced that we're done with defining human intelligence, let alone intelligence as it pertains to other species. See, for example, "rationailty quotient"
http://www.tvo.org/cfmx/tvoorg/theagend ... 20:00:00.0

[htom]

Beautiful work, Rob.

"Potentially intelligent", we (and the dolphins) have the potential to be intelligent. Sadly, we don't often live up to that potential. But that's a rant for a different day. Mr. Stevenson demonstrates the proper use of the potential.

I'll go and look for Mr. Einstein, and other potential Easter Eggs.

[moonstruck]

Very beatifuly done Rob. Thanks for posting it. I hope someday they have enough photographed so we can click on it with our curser and spin it around like with the Google Earth map.

[moonstruck]

That way we could see what's on the other side

[rstevenson]

Very beatifuly done Rob. Thanks for posting it. I hope someday they have enough photographed so we can click on it with our curser and spin it around like with the Google Earth map.

Hmmmmm, let's see ... . My Calculus mid-term is tonight and my Chemistry mid-term is Friday morning ... ... . Yeah, I've got time.

I was joking when I wrote the above, but I just thought of how to do it. Anyone know of a good gif-based animation of the earth rotating? I should be able to map ... ... no, never mind. I just thought of a problem. Maybe later.

Rob

[rstevenson]

Counting the atmosphere, the earth is about 50% oxygen with half the remainder being silicon. Then there's a bunch including (in descending order) aluminum, iron, calcium, sodium, potassium and magnesium. At that point we're below 1% for each of the rest of the elements.

That sounds like the figures Wikipedia gives for the crust alone. For the planet as a whole, the iron figure is significantly higher (at 32%, opposed to about 5% in the crust).

Uh, oh! My Chemistry prof wrote the textbook I was quoting. He would not be happy I misquoted him. He did, of course, say that this was the list for the crust plus the atmosphere.

[Note to self: a passing mark is in the details!]

Rob

[Ann]

If iron makes up 32% of the Earth, does that mean that it makes up 32% of the mass of the Earth, or 32% of the volume of the Earth, or 32% of the molecules of the Earth?

And I'd really like to know how much of the mass of the Earth that comes from iron.

Ann

[Henning Makholm]

If iron makes up 32% of the Earth, does that mean that it makes up 32% of the mass of the Earth, or 32% of the volume of the Earth, or 32% of the molecules of the Earth?

Mass.

The other two options wouldn't be sensible: Most of the matter in the Earth does not form molecules (at least not in the nice clear-cut way we half-learn in school), and volume is not additive when you mix things, so a breakdown by volume would depend on very arbitrary choices along the way.

[zzwerzy]

My bad. This was bugging me so I came back and looked again. Yes, you're description is correct and I am ashamed! No more commenting after 2 am!!!

Thanks for all the wonderful images and information.

zzwerzy

Yes, beautiful. But Africa and Antarctica - not so much.