A Mission to the Earth’s Core

Published in the December-2003 issue of Analog Science Fiction & Fact Magazine ^ | 06/22/2003 | by John G. Cramer

[King Prout]

I see. And exactly how much mass does a star have, that has undergone collapse to a neutron star (with unimaginable density), and then grown back ?

a lot more mass than the Earth - on the order of several orders of magnitude.

First, not all planets are life-bearing types.

irrelevant. nova and supernova are inconcievably destructive ka-booms. the impulse of the shockwave of even one in a system as small as Sol's would scatter whatever it did not destroy outright.

Second, what law of the universe would keep such remnants from ending up packed 'a bit too closely' , and being the constituents of a solar system?

gravity. such massive objects would not be captured in orbits around so small a star as Sol - they'd all fall into the shared center of mass.

IIRC, at least one accretion disc has recently been discovered which conforms fully to the conventional postulation of the formation of this solar system. no dead-star cores involved.

[Dawsonville_Doc]

I believe that *some* of what you say here is correct.
1. The Earth is indeed not hollow (what a surprise!)
2. The Earth, and everything on it, is "starstuff".

Now, here's the kicker-
3. The "stuff" isn't from a single star. It's from LOTS of stars. A supernova spreads matter over an incredibly wide area. Have you ever looked at the Orion Nebula? That's "starstuff" as well, and new stars are forming inside it. Same with the Eagle Nebula. Same with lots of nebula. Some of those stars have accretion disks of matter that is caught by the gravity of the system. Yep- more of that "starstuff" there. Some of that matter may get together and form planets around those stars.
4. A star that becomes a neutron star after going supernova does *not* have an "attendant black hole". If you have evidence to the contrary, I'd love to see it.
5. Neutron stars are *massive*. On average, about 1.4 solar masses, and about 20 km in diameter. We *know* the mass of the Earth, and it isn't even close to that.

Again, if you have published evidence stating otherwise, do share.

[tet68]

And just how is he going to get 100 million kilos
liquid all a once?

[_Jim]

First, those who expressed a healthy amount of skepticism as to the accuracy of a certain stated number:

Centurion2000:

WTF ? a 30 meter BALL of melted iron is gonna weigh MUCH MORE.

Zeko:

Something's wrong here -- a solid iron sphere about 30 meters in diameter would weigh more by a factor of about a million . . .

Close, but no cigar (you have to actually call it to nail it)

Oberon:

The cut-and-paste failed...the actual number was probably supposed to be 10^8

Ding! Ding! Ding! We have our first winner!

Fredgoblu:

Methinks the author missed a few zeros.

familyop

Yes. Stevenson's "modest proposal" is probably some kind of left/liberal satire.

King Prout:

maybe 10⁸ kg?

Ding! Ding! Ding! We have our second winner!

Now, that portion of the original document on the caltech.edu website from which the posted story was developed:

I describe here a mission to Earth?s core in which a probe is imbedded in a large volume of liquid iron alloy that migrates to the core along a crack propagating under the action of gravity.

The time to reach the core is ~ a week and the minimal required volume of iron ~ 10⁸ kg, or about one hour of Earth's iron production.

And last but not least, we have the original document from which specifics were pulled for the posted article:

mission_to_core_(annot).pdf

[Oberon]

That's just one of the many technichal difficulties with this scheme. I think I have the answer, though.

You could put a refractory dam around the hole where you want to dump the iron. Inside this dam, pile up a small mountain of powdered aluminum/ferric oxide mixture. Add one strip of magnesium ribbon to ignite, and voila! A thermite reaction yeilds a swimming pool full of molten iron toot sweet, baby.

I wouldn't stand too close, though.

[SunkenCiv]

Thanks to Vannrox for posting this topic. Volcanism is a well-studied, though poorly understood, source of GGG pings. ;')

Please FREEPMAIL me if you want on, off, or alter the "Gods, Graves, Glyphs" PING list --
Archaeology/Anthropology/Ancient Cultures/Artifacts/Antiquities, etc.
The GGG Digest -- Gods, Graves, Glyphs (alpha order)

[Ernest_at_the_Beach]

Thanks for the ping!