Lonely Planets

by David Grinspoon

  in myriad forms. It was a chemical Kama Sutra where molecular adven-

  turers got busy, trying anything at least once. The result was a period of

  “chemical evolution,” a primitive molecular survival of the fittest

  where stability and longevity were the only criteria for success.

  Molecules that found longer-lasting, more stable configurations were

  naturally selected. Such hardy structures, favored by the gods of trial

  and error, became concentrated in the primordial sea.

  And then it happened. This magic moment. Carbon chemicals, inno-

  cently cavorting in water, hit upon something new and extraordinary:

  structures that could make copies of themselves. Eureka! In the 10-billion-

  year history of the settling down of matter, and the bubbling up of order, a

  powerful new force was unleashed: heredity—the preservation of useful

  information. Those structures that could copy themselves most accurately

  and efficiently multiplied like rabbits in a world without foxes. Self-

  replicating chemicals rapidly populated the young oceans.

  We don’t know what the first self-copying chemical mechanism was,

  but we do know which one stuck, because it’s still here, working its

  magic: DNA. In a sense, there has only ever been one strand of DNA,

  dividing and multiplying on Earth for nearly 4 billion years. DNA

  never dies, it only improves. Evolutionary tributaries dry up and disap-

  pear, but the mainstream of DNA-driven life keeps on growing. Barring

  *The Miller-Urey experiment, described in chapter 3, demonstrated that these molecules are easy to make in conditions simulating those of the young Earth.

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  disaster, it will flow onward until, 5 billion years hence, our dying Sun

  becomes a red giant star and incinerates the Earth. This helical miracle

  may even outlive its star of birth, if we leave and take it with us.

  DNA is a molecule that may have achieved immortality. And we,

  along with all other terrestrial life, are its by-products, reproduction

  mechanism, and life support system. We are the ships that DNA has

  devised to navigate the world. But when the machines get smart

  enough, they can take over the factory. With the first faint, fragile glim-

  mering of intelligence on Earth, we can see the potential for a new, as

  yet unwritten, chapter of Cosmic Evolution, the self-aware phase in

  which matter wakes up, takes a look back at where it’s been, and con-

  sciously decides how to proceed.

  W H A T ’ S T H E P O I N T ?

  This new origin story need not replace all others, but it does augment

  them. I do not mean to be cavalier in comparing the story of Cosmic

  Evolution to the world’s great religious texts. Obviously, this story does

  not address all the needs met by our older origin stories. It doesn’t

  answer the question “Why?” about anything. It provides us with no

  rules on how we should live, at least not in any obvious way. I do not

  subscribe to scientism, the view that science is all you need. If pressed, I’d say that John Lennon’s view that love is all you need is closer to the

  truth. But a combination of the two is even closer.

  So then, what’s the point? How does it help us if it cannot provide us

  with a purpose or tell us how we ought to live? Why science’s attitude

  of superiority? Well, the attitude is not justified. But there is a point.

  Several, actually. Science does not tell us why we are here, but it has

  taught us a lot about where “here” is. Science limits the range of the

  possible and, in so doing, points us toward what is true. And I think

  that a careful reading of this story does convey some powerful messages

  that I, personally, am not afraid to call religious.

  You, me, everything you can see except the stars, and a great deal

  that you cannot, were all once mixed together in one giant, diffuse

  cloud. Even the stars themselves, and all the distant galaxies imaged by

  the Hubble, we and they were all one, even earlier, when the universe

  was a hot little ball of fire. Once a singularity, always a singularity.

  That Zen master hot dog vendor doesn’t have to make you one with

  everything. You already are.

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  L o n e l y P l a n e t s

  Cosmic Evolution carries a message of complete and profound unity,

  which I think can be read as a reason to care deeply for all things, espe-

  cially for the living Earth and its creatures, the most highly evolved

  local products of matter’s slow climb from formlessness. Against this

  backdrop, the anthropogenic mass extinction that we are currently

  inflicting upon Earth seems a desecration of cosmic proportions.

  Maybe there is a moral to this story.

  F I E R C E M A G I C

  Last night, I was up late writing this chapter, trying to distill the story

  of Cosmic Evolution into a brief narrative. I had to take years of

  detailed study, throw out most of the details, and try to extract the core

  events, the highlight reel of the universe. With visions of galaxies danc-

  ing in my head, I drifted off to sleep and had a vivid dream. An earnest

  woman who might have been Native American—she looked like the

  poet Joy Harjo—was telling me about something important that had

  just happened to her, something that made her realize how incredibly

  fleeting our lives are. She implored me to remember to treasure each

  day.

  I don’t know whether this dream was related more to the cosmic

  timelines ripping through my mind or simply to the emotionally mixed

  experience of shutting myself off from my people and my planet for

  some of my precious days to get some writing done. But, I awoke that

  morning with these Joy Harjo lines in my head:

  I can hear the sizzle of newborn stars, and know anything of

  meaning, of the fierce magic emerging here. I am witness to flexi-

  ble eternity, the evolving past, and I know we will live forever, as

  dust or breath in the face of stars, in the shifting pattern of winds.

  This poem expresses another lesson of Cosmic Evolution. That we

  are immortal. There is life after death in a sense that is completely real

  and does not require blind faith. You don’t have to see yourself as sepa-

  rate from everything else. We have been here, gathering ourself for at

  least 10 billion years. This is just the beginning. We’ll live on for tens of

  billions more.

  We can’t study life as a cosmic phenomenon without studying the

  universe as a whole. The seeds of life were planted in the early primeval

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  fireball, and the roots of life grow in the very fabric of space, time,

  energy, and matter. What we don’t yet know is how to place ourselves

  in this story. Are we peripheral or accidental, or somehow integral and

  central to the main theme? The meaning will not be clear until we find

  out if there are other souls circling distant stars, others who have

  emerged from this same cosmos into an awareness of their own.

  Either way, this is our story. It grounds our existence in the unfolding

  of the universe. We carry reminders of it in every cell, every atom, ofr />
  our bodies. We have learned that our ancestors are stars. And we are

  water— enclosed sacs of Earth’s salty oceans that have conspired with

  carbon molecules to achieve mobility and a fledgling form of con-

  sciousness. Looking out, and looking back, we see that we are the eyes

  of the world and the soul of the galaxy. We just don’t know whether we

  are the only ones.

  Each of us, growing up, reaches a point at which we become curious

  about our origins. We ask our parents challenging questions about

  where babies come from and which came first, chickens or eggs. Here

  on this rocky speck of living stellar afterbirth the climb of matter has

  somehow arrived at what we proudly call intelligence. Here the uni-

  verse has grown up to an age where it wants some answers about

  its own provenance. Here on Earth, the cosmos has awakened from a

  12-billion-year dream. It seems that our consciousness, in inchoate

  form, was here all along, waiting for the right conditions to precipitate

  out of inanimate matter. Elsewhere, is it slumbering still, or were we

  among the late sleepers?

  Why here, why now? Once life got started, it quickly embedded itself

  in the workings of the planet, altering the atmosphere, the oceans, the

  rocks, and the soil. As life has adapted to the changing environments of

  the Earth, Earth has been remade continually by life. So ancient is this

  partnership that it is impossible to know what Earth would have

  become if it had not become alive some time around its 500 millionth

  birthday. What happened on Earth to give rise to one species that

  makes music, Mandelbrot mandalas, and Mars probes? How were we

  transformed from a newly formed, warm, wet, organic-rich planet into

  a profuse, prolific biosphere that has now started looking back out at

  the planets, stars, and galaxies to piece together this story? To better

  understand the context of our awakening to consciousness, and to

  assess its significance for life on other worlds, we must closely examine

  the history of Earth and its life.

  Earth Birth

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  If seeds in the black Earth can turn into such beauti-

  Image unavailable for

  ful roses, what might not the heart of man become

  electronic edition

  in its long journey towards the stars?

  —G. K. CHESTERTON

  Did I know you?

  Image unavailable for

  Did I know you even then?

  electronic edition

  Before the clocks kept time

  Before the world was made

  —U2, “WILD HONEY”

  I N S I D E O U T

  Who are we to say that our Earth is such a special place? Like parents

  certain that their baby is the cutest ever born, of course we think our

  planet is the chosen one. Nevertheless, in all modesty, you have to

  admit: Earth stands out. Ours is the only planet around these parts able

  to tell its own story.

  All other local planets appear to be dumb as rocks. Somehow, our

  world has sprouted eyes, hands, minds, and mouths, not to mention

  microscopes, telescopes, and microchips. Since we seem to have, for

  now, become Earth’s only voice, our reconstructions of geological his-

  tory amount to an autobiography of the planet. Many pages are miss-

  ing, scattered by the winds and crumbling with age. The story is written

  in the rocks, fossils, and whiffs of ancient air. As we learn to read it, our

  world begins to tell its tale.

  We planetary scientists are used to taking a global view. We’ve had

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  no choice, really. Holism is easiest when you know next to nothing, and

  we’ve learned about the other planets from the outside in. At first we

  knew them only as bright lights wandering the sky. Telescopes trans-

  formed them into dusky disks with faint, suggestive markings.

  Spacecraft have turned them into real places with landscapes of rocks,

  dunes, riverbeds, craters, mountains, and ice. But each is still a tiny dot

  in the sky that you can cover with your little finger.

  When planetologists look at life on Earth, we regard our own world

  as we might examine another planet in searching for signs of life. From

  space we don’t see organisms, cells, tissues, and chromosomes. We see

  global patterns of vegetation and habitation, and the telltale traces life

  has left in the atmosphere and oceans. We look at the totality of life to

  see what distinguishes our planet from nonliving worlds. The planetary

  perspective allows us to see large-scale features and trends that we

  might miss if we stayed mired in the details.

  Because we spend our time unraveling planetary histories that have

  unfolded over billions of years, ours is a time-lapse view of terrestrial

  evolution. In this fast-forward movie of Earth, the coming and going of

  individual species, mountain ranges, oceans, and ice ages are acceler-

  ated to a blur. We see only those major transformations that would be

  visible from far outside, catching the eyes (or the antennae) of inter-

  ested aliens with long attention spans.

  What follows in the next few chapters is a brief account of some of

  the more memorable, formative events in the maturing of Earth. My

  purpose is to make sure that, when we turn outward to consider life in

  the rest of the universe, at least our guesswork will be educated. Like all

  biographies, this will be highly selective. In particular, I’ll focus on

  developments that seem to have been pivotal for the continued flower-

  ing of life and eventual awakening of consciousness here, and that

  might be part of the story on other worlds as well.

  We won’t know anything with certainty about the evolution of life

  elsewhere until we find some, or it finds us. From a cosmically enlight-

  ened perspective that we do not currently enjoy, the path of life on

  Earth may appear either typical or unique. Either way, it is worthy of

  careful study, if only because it is the path that we ourselves have taken

  from the inanimate trajectories of elementary matter, through a nested

  series of communal bodies with ever subtler reflexes of survival, on into

  the first sputterings of conscious awareness.

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  L o n e l y P l a n e t s

  B O R N I N S T E A M

  As the newborn Earth grew by the assimilation of lesser worlds, her

  gravitational reach extended farther into space. Stray planetesimals or

  comets wandering nearby were sucked in, feeding the rocky little bun-

  dle of joy, increasing her appetite for more. As the planet’s strength and

  hunger expanded, approaching bodies were accelerated to ever faster

  velocities and incoming rocks increased their punch. The harder they

  came, the harder they fell. Mountains of rock, metal, and ice came

  crashing down, each one raising a massive spray of vaporized rock and

  leaving a round pool of incandescent magma.

  Though Earth was dotted with newly formed craters, each briefly

  heated to thousands of degrees, on the whole the planet stayed quite

  frigid. In its earliest stages, the growing planet had no atmosphere at

  all, s
o these puddles of molten lava were touched directly by the frozen

  void of space. Some heat was buried underground, but the surface

  cooled quickly, radiating away heat just as fast as the impactors could

  bring it in.

  All that changed when Earth began to cloak herself in steam, which

  was liberated from the falling rocks themselves. Virtually all of the

  boulders that assembled to make the Earth contained some water,

  locked inside the crystal lattices of minerals. If you hit such a rock hard

  enough, the water is knocked loose from its mineral cages. Once Earth

  grew beyond a certain size, roughly half her final diameter, every new

  rock fell too fast to hold its water inside. Now each impact spat out an

  angry puff of vaporized water and carbon dioxide, which, bound by

  gravity, began to accumulate around the growing sphere. This “impact-

  generated atmosphere” was Earth’s first air. Soon our planet was blan-

  keted in steam.

  Water vapor is a greenhouse gas, meaning it absorbs infrared radia-

  tion and helps a planet hold on to its heat. Our early steam atmosphere

  formed an insulating blanket, swaddling the infant Earth. Giant bodies

  from space continued to fall at cosmic speeds, but now the heat from

  their impacts was trapped. The young Earth, insulated by its new steam

  atmosphere, became absurdly hot, melting surface rocks, which liber-

  ated still more steam. Our planet was covered by a global ocean of

  molten rock and enveloped by a dense, sweltering atmosphere.

  Sometime during those early, steamy days, before oceans appeared

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  and life began, the young planet suffered one truly Earth-shaking

  impact that, traumatic as it was, would later prove essential in building

  its unique character. In the chaos of planetary growth, when the solar

  system was crowded with planetesimals on crazy, intersecting orbits,

  another planet, about the size of Mars, plowed into Earth. The glancing

  blow blasted off a big chunk of Earth, forming an orbiting ring of

  vaporized rock that later coalesced into our Moon. This apocalyptic

  event melted our planet in its entirety and had major effects on its later

  atmospheric and geological evolution. Ever since, the Moon has influ-

  enced Earth in numerous ways, slowing its rotation, raising tides in its

  oceans, steadying its spin axis and climate, and inspiring its poets and