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Planets of Gold

You are here. Credit: NASA.

You are here. Credit: NASA.

1990 is in the past, but its artifacts remain. The first car that was wholly mine was a 1990 Honda Civic, a blue sedan with air conditioning and power everything. The I-35-to-I-20 interchange in Fort Worth, Texas was completed in 1990, the continent’s north-south traffic now funneled through a city-bisecting concrete trough. A year later, there would be an optional war that would shape the wars we have today. Even obvious things are hard to see.

Relenting to Carl Sagan’s years of prodding, in February 1990 NASA directed the creaky Voyager 1 spacecraft to turn its camera back the way it had come. The risk of the Sun burning out the camera no longer of concern–the way ahead held nothing to photograph–tiny heaters warmed the old-style vidicon TV tube. Unused for years, no one knew for certain if the camera would work after a deep soak in gelid cold and brutal radiation, or the motorized platform that moved it. From six billion kilometers away, the old 1970s-era tube would need long and steady exposures to gather enough light to make images.

Everything worked. 60 images were captured and returned to Earth. Two planets didn’t make an appearance: Mercury was too close to the Sun, and, due to a trick of the light, Mars was lost to reflections. Another trick of light places Earth in a sunbeam. I don’t know if any pulpits made any pronouncements based on this ostensible sign, but I wouldn’t be surprised.

“Pale Blue Dot”, as our single-pixel portrait has come to be known, is now something out of time. A cultural undercurrent, it was not photographed by anyone. It is an artifact made by an artifact. Both may last forever.

Time stretches on in little drops. If you go faster, the drops merge; if you go slower, they separate. There is no up or down, more or less: you can only move relative to something else, which is also moving. There is no solid place to stand, unless you go very fast, in which case you can become almost still. At almost the speed of light, time slows to a near stop. Only light holds the privileged place. Light is the only still thing, because light, the fastest thing there is, does not experience time at all.

Light from 1990 flows outward. Diffusing over distance, it becomes harder to pick out, but that blue glint of 1990 Earth courses outward, forever. Bits here and there will be absorbed by planets and meteors, more likely dust and gas, if anything. But the universe is almost all nothing. Most of the light will go on, always free. No time will pass for it. It will always be new.

The radio transmission Voyager 1 sent back to us is also light, just at an energy we can’t see. A very tiny portion of it landed on a parabolic dish, was washed and concentrated by equipment cooled to a hairsbreadth of absolute zero, and recorded as ons and offs. Almost all of it passed us by and flew on into the dark. Data no one will ever read still retains the sensibility of that long-ago day, and always will.

Old Kodachrome memories of grandparents’ houses and elementary schools sit in albums and redden with time. The light that exposed the film is long gone, turned to tiny heat that drifted away. Energy is neither created nor destroyed, only its temporary condensation held in something we can appreciate. Photographs won’t last forever, but the light that made them will.

We know just enough about the world to begin to ask questions as profound as they are unanswerable. Logic is our friend here. In a big enough place with endless time, the possible is certain.

I read a planetary science article that described a new conclusion about how Earth got its gold. Previous to this new work, it was thought that all the gold humans have ever panned from streams or dug out of mines came from our planet’s formation billions of years ago. Staring at apple trees and fiddling with calculators, the authors had a hypothesis this couldn’t be right. What we know of geology and planetary formation, applied to a computer model of the early Earth, prove that all the Earth’s original gold is too dense to have stayed anywhere near the surface for humans to find. Due to its density, all that primordial gold must have fallen down to the core, back when the planet glowed red hot. So, the Earth should have no gold. (Whether this applies to lead, or uranium, or any heavy elements is not explored.) But, there is gold. Studying meteorites and comets suggest that all the gold available to us was deposited in countless impacts, over millions of years, as comets and meteors pelted the early Earth.

On its own, this is one of those interesting observations that can make for bar chatter that proves you’re a square. But this stuck with me.

Well, I thought waiting for the bus one work day, if all the gold fell to the Earth’s core, it must still be there. In among the liquid iron that churns and makes the magnetic field, there must also be gold. Giant globs of it, mountains of it. So much gold that we’d make wires out of it instead of copper. 

The bus comes.

Oh. If that’s true for Earth, that must be true for other planets like Earth, like we are finding these days. And the universe is 15 billion years old, give or take, so there must be countless dead Earths. If they were closer to their star, and their star blew up, those other Earths would disintegrate, blown out into the galaxy, the debris cooling down. 

This is what meteors and asteroids are: bits of junk that never got big enough or to the right place to become a planet, or a planet ground up by their neighbor’s gravity. I’m guessing Jupiter smashing up a proto-planet is what made our asteroid belt between Mars and Jupiter. (If Mars had been a little closer to Jupiter, or managed to grow a little bigger in the Solar System’s first millions of years, it might have been ground up too.)

Through tunnels and over bridges the bus goes. Steel girders carry streets and make columns. Some meteors are solid iron and nickel. You can turn them on a lathe. Those rocks must be the frozen hunks of planetary cores. They were broken up and frozen, and they rain down from time to time. 

Do you see what I see?

Throughout the galaxy, there must be asteroids of gold. Smashed apart in impacts or blown up by dying stars, a rocky planet’s core cracks like an egg and the glowing contents spill out and freeze. All that stuff trapped inside for billions of years is released again: the gold, the lead, every scarce oddball on the periodic table in rocks as big as cities, as mountains, as continents.

Planets of gold surround us.

Mars is hot again. There’s a movie made from a novel about a stranded astronaut, and a semi-autonomous robot of the kind Carl Sagan dreamed of is wheeling around the surface, tasting rocks and sending pictures. Fools who should know better think a one-way trip to Mars is a good use of precious resources instead of cause for a serious talk about watching too much television. A few people are kind-of interested in these sorts of adventures. Most feel more like Gil Scott-Heron, back when we were only talking about cities on the Moon.

We will never go. Such an undertaking is too expensive, and that is how we really measure things. That going would kill most people before they arrived, and contaminate Mars with Earth microorganisms, are secondary reasons.

Still. Wonder costs nothing. We have plenty already, right here, that we don’t know about. I understand running away from problems, but that only gets you so far. Better to sort out what’s a problem and what’s something you can act on.

It’s certain there are others out there, if not looking through telescopes then just looking up and wondering. It’s enough to imagine, out there in the dark and never to be found, whole worlds of silver and gold, time and distance making it so they will never be valuable, only beautiful. That is a worthy faith.

Golden. Credit: ESA; Hubble, M. Kornmesser; and ESO, L. Calçada and L. L. Christensen

Golden. Credit: ESA; Hubble, M. Kornmesser; and ESO, L. Calçada and L. L. Christensen


One comment on “Planets of Gold

  1. This is beautiful. It’s a gentle reminder to look up again.

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