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NASA's 1970s concept for space colonization. Image: NASA
Assuming human deep space travel turns out to be not just incredibly dangerous, but perhaps “crazy
idiotic" and "laughable," as Harvard biologist Gary Ruvkun put it, the
tenacious dream of an interstellar civilization forces some out-of-the
box thinking. What if, instead of rocketing humans to other planets, we
made an exact copy on site?
Adam
Steltzner, the lead engineer on the NASA JPL's Curiosity rover mission,
believes that to send humans to distant planets, we may need to do one
of two things: look for ways to game space-time—traveling through
wormholes and whatnot—or rethink the fundamental idea of "ourselves."
"Our best bet for space exploration could be printing humans, organically, on another planet," said Steltzner on stage at Smithsonian Magazine’s Future Is Now conference in Washington, DC this month.
Many of science’s brightest minds think that the only way to guarantee the long-term survival of the human race is to colonize other planets—problem
is, we have no clue how to safely travel to Mars, let alone further
into our cosmic neighborhood. By sending instructions on how to print
ourselves to far-flung locales, we could skip the trip.
The
"printing" idea starts out by encoding human genetic information in
bacteria so that our DNA can hitch a ride to another planet. Scientists
recently discovered that microbes can survive the trip from Earth to Mars,
so the theory is, why not bring some genetic code along next time? Then
once the DNA-toting microbes arrive on the new planet, the building
blocks of life are reassembled as a human being.
"Once you propose terraforming, you might as well propose sending bacteria with human sequences. That's not that crazy."
"Maybe
we will colonize other worlds not with astronauts in space suits, but
with bacteria," said Steltzner at the event. "Those considerations seem
beautiful, fantastic."
Beautiful, fantastic, and totally bonkers. Interest piqued, I called up Ruvkun—who along with George Church, his colleague at Harvard Medical School’s genetics department, pioneered the DNA space travel concept—to find out if the idea is just futurist hubris or actually feasible. The short answer is, it’s a little of both.
The printing humans concept is not mine, but belongs to Ruvkun, Church and others Havard Med Dept of Genetics. They think deep and forward.
— Adam Steltzner (@steltzner) May 17, 2014
Ruvkun
told me that it is possible to encode segments of human DNA in bacteria
and have it survive the trip to other planets. “Like using bacteria
like computer memory,” he said. 'It's sort of like an iPod that you send
to another planet. And the bacteria can store information very
densely."
It’s
an extension of the idea to engineer bacteria to send into space to
terraform Mars. These microbial pioneers would stimulate the evolution
of a new biosphere, the theory goes, providing oxygen and food and the
environment that Earthling settlers would need to live on the red
planet.
"Once
you propose terraforming, you might as well propose sending bacteria
with human sequences," said Ruvkun. "That's not that crazy."
What is
potentially crazy, however, is the plan to reassemble the sequence on
the other side. At this point, that’s beyond what’s we’re capable of.
"We don't have any ability to sort of reassemble a human from DNA,” said
Ruvkun.
But
it’s also not entirely outside the realm of possibility. As genetic
engineering, cloning, and bioprinting technology advances, it’s
providing a lot of food for the imagination. If you put a 100th of a
human genome into bacteria, Ruvkun said, you'd have to assemble 100
human segments, Ruvkun said. That seems doable.
"We're only 50 years into the DNA era," he said. "Five thousands years in, we'll probably think of that as a piece of cake."
But
engineering bacteria in a university lab is one thing. If you’re trying
to reconstruct an entire human on distant planet with no intelligent
life, who’s even doing the reassembling? And this is where the idea gets
really wacky.
If
you want to roll with the terraforming scenario a bit further, you can
imagine the human-encoded bacteria reassembles naturally, through
organic processes, to eventually evolve into descendant organisms—sort
of restarting the human population.
“Maybe that process has happened before,” Steltzner told me over the phone this weekend. “Maybe that's how we got here.”
Image: Rick Guidice/NASA
That
line of thinking opens up a host of questions about how life came to be
in the first place. Did someone else terraform Earth to create us? Do we share a microbial ancestor with Mars? If
we custom-make life to survive on other planets, are we ‘playing god?’
Is ‘life’ more than a reconstructed genome? But let’s snap that
Pandora’s Box shut for now and move onto scenario B: artificially
constructing our biological building blocks after they hitchhike through
deep space.
One idea floated by Steltzner is that we beam the human genome into the universe through
radio waves—like we're already doing to try to communicate with
intelligent life—and see if anyone receives the transmission and can
figure out how to interpret it.
Maybe
we send along detailed instructions with the signal, or encode a user’s
manual of sorts in the DNA-carrying bacteria. Maybe we even send a robot to another planet,
wait a thousand years to make sure we trust the machine, and then "beam
the information about a human being and tell it to genetically
construct the human," Steltzner mused.
"The
idea of 3D printing is, something's created out of matter at the
location, just with the information. And that's kind of what we're
talking about here,” Steltzner said. "That kind of feels like a very
fancy 3D printing to me.”
If we believe it's possible to print a Martian organism on Earth, could it work the other way around?
It
sounds far-fetched, but it’s an area of biotech geneticists are
currently exploring. Being able to store and transmit genetic code the
same as any other kind of data is the principle behind the “life printing” gadget being
developed by biologist Craig Venter, the US biologist that’s famous for
helping map the human genome and creating the first synthetic life.
Venter is developing a “digital
biological converter” device that can transport a digital DNA file, at
the speed of light, and recreate the original lifeform in the new
location from that data. He calls it biological teleportation, but it’s
more like a cosmic fax.
Venter believes the process could be used to “print” alien life, if there is any, here on Earth.
If, say, the Mars rover discovers microbes on the planet, it could beam
back digital copies of the genomes to sequence here on Earth. There's a
prototype already, which unsurprisingly has attracted the support of
NASA and DARPA.
So
if we believe it's possible to print a Martian organism on Earth, could
it work the other way around? At this point, Venter’s experiment is
only tackling life-printing at the individual gene level, but
single-celled organisms like bacteria are next in line. “More complex creatures,” the New York Times reported, “earthly or Martian, will probably never be possible.”
Probably
not. But in Ruvkun’s view, this method of “human” space exploration is
worth thinking about, if for no other reason than it’s the least
unlikely of all the unlikely schemes to colonize the cosmos.
If
we're going to talk about interplanetary settlements anyway, we might
as well discuss the strategies that aren't definitely scientifically
impossible, he reasoned. We know which laws of physics are standing in
the way of transporting people lightyears through the universe, but
there aren't obvious laws of nature preventing us from sending
DNA-encoded organisms to propagate the species on other planets.
"This
is completely speculative," Steltzner said at the end of our interview.
"But it doesn't require you moving faster than the speed of light, and
it doesn’t require infinite amounts of energy.”
