Do Aliens Exist Human Technology May Prevent Us From Finding Out
Every evening in Maui, a telescope perched atop a volcano captures particles of light
in the universe with the world�s largest digital camera. Normally it searches for asteroids
dancing across the cosmos. But one night last October, it locked its gaze onto something
remarkable, an unidentified flying object moving quickly through space, seemingly from
another solar system. Or at least that�s what astronomers at the
University of Hawaii concluded when they discovered it. At first, they thought it was a comet,
then an asteroid. But within a month, they realized the object was long and thin and
unlike any asteroid known to science. They named it �Oumuamua�a Hawaiian word that
means �messenger from the distant past.� Thousands of miles away, a Harvard astronomer
named Avi Loeb learned of the mysterious object as well. Soon, he began pondering an enticing
possibility: that �Oumuamua was actually an alien spacecraft sending signals back to
its creators. This theory may sound a bit out there. But Loeb isn�t some crackpot
looking for little green men in a spaceship. He and his colleagues are part of a growing
number of top-tier scientists who are applying the same rigorous standards they use on other
scientific issues to tackle one of the biggest questions facing humanity: Are we alone in
the universe? Americans have long been fascinated by the
possibility of alien visitors. A 2001 Gallup Poll (the most recent one available) found
that 33 percent of Americans believed aliens have visited the Earth. But scientists�both
inside and outside the U.S. government�have been reluctant to take such claims seriously.
From the 1947 weather balloon crash in Roswell, New Mexico, to crop circles in England, they�ve
largely joined the debate only to debunk some very dubious claims. They�ve also lamented
the lack of distinction most people make between alien landings�which haven�t occurred�and
the possibility of future alien contacts (which could indeed happen). �We always get the
UFO question,� says Dan Werthimer, astronomer at University of California, Berkeley. During
public appearances about the search for alien life, Werthimer says, people often say, �why
bother, because E.T.�s already landed here and kept secret in some military installation.�
But while UFO claims are often hoaxes or the work of conspiracy theorists, the search for
extraterrestrial intelligence�alien life just as smart and technologically advanced
as humans�is a legitimate scientific field.Driving this quest to find life on other planets:
hundreds of millions of dollars and super-powerful new telescopes that look ever deeper into
the universe. Experts disagree on how intelligent life might
try to contact humans. But the resurrected field, known as SETI, is largely based on
the assumption that extraterrestrials�if they are out there and actually trying to
chat�might use the same type of tech that we use to communicate with one another�from
radio signals to flashes of light. Yet that conjecture speaks to SETI�s central
irony. Just as our attempts to find extraterrestrials are becoming more advanced, just as scientists
are increasingly confident we aren�t the only intelligent beings in the universe, humans
are creating more technology-produced noise than ever before, undermining our ability
to detect potential alien transmissions. In fact, SETI scientists say, we are making
so much noise, if E.T. tried to phone our home, we might never get the message.
Look Who�s Talking In 1950, Nobel Prize-winning physicist Enrico
Fermi articulated a riddle�now known as Fermi�s paradox�that speaks to a core
question SETI scientists are trying to answer: If intelligent life exists elsewhere in the
universe, why haven�t we found it yet? Since experts estimate the universe is nearly 14
billion years old, you�d think it would be populated with civilizations other than
our own. One problem: money. The search for extraterrestrials
is very expensive. And the U.S. government and private universities have mostly avoided
funding the required research. The first professional SETI conference, held in Green Bank, West
Virginia, was in 1961, just months after Soviet cosmonaut Yuri Gagarin became the first person
to travel into space. In the 1980s, NASA devoted $1.5 million to $2 million per year to the
search for sentient life in outer space, and in 1990, Congress approved $100 million for
new technology�a significant amount of funding for the field. But just a few years later,
NASA axed that program. �Not a single Martian has said, �Take me to your leader,��
Democratic Senator Richard Bryan of Nevada said during the budget vote that canceled
the funding. �And not a single flying saucer has applied for FAA approval.� NASA hasn�t
funded SETI research since, a decision that pushed aliens to the fringes of astronomy.
Yet in 2015, SETI researchers finally received the necessary funding. And it came in a plot
twist reminiscent of the movie Contact�in which a SETI researcher clashes with government
authorities, only to be rescued by a mysterious billionaire.
In real life, SETI�s wealthy benefactor isn�t secretive. His name is Yuri Milner,
and he�s a Russian physicist and venture capitalist. Named for Gagarin, he sees it
as our �galactic responsibility� to acknowledge the profound luck of our intelligence�and
search elsewhere for its equal. He also dreams about the impact such a discovery would have
on humanity. �There are these moments, that are very rare, that we all feel like one,�
he says. �The rest of the time, we are divided.� Milner decided to bankroll the search for
extraterrestrial intelligence, pledging $100 million over 10 years for an international
project called Breakthrough Listen. �Obviously, there�s no guarantee,� he says. �The
chance of finding it in the next 10 years is small. [But] the significance of that potential
discovery is so large that even the small probability justifies the effort.�
About a third of Milner�s funding goes to the SETI program at the University of California,
Berkeley. Andrew Siemion, its alien hunter in chief, stumbled onto the field after 9/11
left him searching for meaningful work. Since then, he has dedicated his career to trying
to find a sign�any sign�that can be explained only by the existence of technologically advanced
alien life. �The most interesting property of the universe is the fact that intelligent
life exists within it,� he says. Siemion is determined to find out if it exists beyond
Earth. �I believe it to be the most fundamental question we can ask as scientists.�
Milner�s money has vastly improved Siemion�s ability to tackle that question. The funding
has given him and his colleagues the ability�and time�to stare across the universe, using
some of the most powerful telescopes on the planet. �It�s an absolute revolution in
our capabilities,� he says. This artist�s impression shows the first
interstellar asteroid: `Oumuamua. This unique object was discovered on 19 October 2017 by
the Pan-STARRS 1 telescope in Hawai`i. Subsequent observations from ESO�s Very Large Telescope
in Chile and other observatories around the world show that it was traveling through space
for millions of years before its chance encounter with our star system. `Oumuamua seems to be
a dark red highly-elongated metallic or rocky object, about 400 metres long, and is unlike
anything normally found in the Solar System. M. Kornmesser/ESO
Most of these instruments are radio telescopes�giant, ultra-sensitive dishes that receive faint
signals from very far away. Yet these instruments don�t search the cosmos for sound; they
search it for light. Radio waves constitute a portion of the light spectrum�the band
that alien technology would most likely use to reach us, many astronomers believe.
Alien hunters look for radio waves because humans are so fond of using them. Radio waves
can travel miles, letting us hear our favorite talk show while we drive. They can also traverse
light-years and be crammed with information, which is why they carry our television broadcasts,
our mobile calls, and GPS locations. Because radio waves are so versatile, SETI scientists
believe our galactic neighbors might use them to reach out and say, �Sup?�
Scientists classify radio waves by how often they crest; that measurement is the wave�s
frequency. The tighter the crests, the higher the frequency. When it comes to radio waves
from beyond Earth, scientists tune to frequencies between 1 and 10 gigahertz. �That�s the
range in which our atmosphere is pretty transparent and the galaxy is pretty quiet,� says astronomer
Jill Tarter of the SETI Institute in Mountain View, California, which has long been the
leader in the field. Going below that window catches too much noise from the rest of the
galaxy, like radiation from planets or even the humming of a distant black hole. The atmosphere
blocks frequencies higher than about 10 gigahertz. But nestled in that quiet window are 9 billion
possible frequencies, or channels, that aliens could be using.
When the modern search for extraterrestrial intelligence began in the 1960s, scientists
could listen to just one channel at a time. Today, they can tune in to tens or even hundreds
of millions of channels at once, listening for a single note from faraway millions of
times over. This vast capacity increases the odds of us catching an alien message when
it arrives. But it also delivers a ridiculous number of other signals. �Every 10 seconds,
you get a signal,� says Seth Shostak, a senior astronomer at the SETI Institute. �You�d
go nuts if you had to look at all this stuff.�
The new era of SETI is rapidly expanding the investigation. Milner�s money gives Siemion
at Berkeley the means to purchase blocks of expensive observing time on some of the most
powerful radio telescopes in the world�from West Virginia to China. Scientists are looking
at more stars, gathering weaker signals and eavesdropping on new regions of the sky, like
the barely studied Southern Hemisphere, the gateway to the crowded heart of the Milky
Way. The infusion of cash helps not only expand
the search but also rule out possibilities. We have no galactic caller ID, and so every
plausible signal must go through a battery of tests to confirm whether it�s E.T. on
the other end of the line. So far, not a single signal has passed those tests.
Yet as Tarter famously put it, concluding that we must be alone, simply because we haven�t
heard aliens yet, is like scooping up a cup of seawater and deciding there are no fish
in the oceans. Scientists have calculated we need to comb about a million star systems
to find new friends. So far, says Shostak, �we�ve looked at
only a few thousand.� Alien Emojis
Beginning in 1998, an unidentified radio signal left astronomers at the Parkes Observatory
telescope in New South Wales, Australia, stumped. They knew the sound was coming from somewhere
nearby, but they had no idea of what it was. Finally�after 17 years of searching�they
found the culprit: impatient staffers opening a microwave oven while it was still running.
Though SETI scientists believe aliens would likely use similar technology as we do on
Earth, that assumption poses a fundamental, possibly insurmountable, challenge to their
search: Our own chatter makes it immensely difficult. Cellphones, Wi-Fi and GPS all rely
on radio waves. Those waves occupy the same channels researchers use to listen to for
E.T. And because our devices are so much closer to the telescopes, the signals are much stronger.
�If E.T. is broadcasting in the cell phone band,� says Werthimer, �we�ll never
find him.� Every time we text an emoji, we potentially make SETI research more difficult.
Sorting the alien wheat from the human chaff, says Siemion, is the hardest part of the search
for extraterrestrial intelligence. Local regulations mitigate the interference.
South Africa is currently building a massive array of radio dishes and trying to move local
television and phone service to radio-free technology to reduce the disturbance they
will otherwise pose. Federal and state quiet zones shelter the Green Bank Telescope in
West Virginia, and its staffers help neighbors produce less interference. Sometimes, they
even drive around in a van equipped with a radio antenna to track down chatter.
South Africa is currently building a massive array of radio dishes
But such measures aren�t enough. Astronomers want to build telescopes in places where there
are fewer people, but it�s not easy. The remote location of the Parkes telescope might
make it conducive for hearing E.T., but it also increases the risk of disruption from
livestock. The electric fences corralling the animals emit radio waves that interfere
with SETI work more than cellphones do. �We probably have more problems with cows around
Parkes than these other things,� says Matthew Bailes, an astronomer at the Swinburne University
of Technology in Australia. Nearly everything we do generates signals, and eliminating them
essentially means eliminating modern life. Even when the land is silent, though, radio
interference still comes from above. An ever-increasing number of satellites broadcast signals from
the sky that radio telescopes pick up. Eradicating this sort of interference says Tarter, consumes
about half the computing power of her institute�s SETI research. That�s a bit like your phone
spending half its energy ignoring your neighbor�s calls or text messages.
Astronomers who study natural phenomena, like clouds of space dust or dying stars, can ignore
everything that looks artificial. But scientists looking for alien life can�t do the same.
The types of noises that are interfering with the search, says Siemion, are �exactly what
we�re looking for.� Which means impatiently waiting for a frozen
dinner to heat up could potentially ruin our chance of finding another civilization.
�Delicate Creatures� Not everyone, however, is convinced that the
assumptions of radio astronomy make sense. Shelley Wright, an astrophysicist at the University
of California, San Diego, is one of them. As she sees it, there�s no knowing what
technology another civilization might possess and what means it might use to say hello.
�There�s really no reason to think aliens would use the radio over laser,� says Wright,
�over something else we haven�t even invented yet.�
Fiction has articulated the problem well. In Story of Your Life, for instance, an expert
translator struggles to decipher an alien language (the 1998 novella was the basis for
the movie Arrival). Or in Babel-17, a 1966 science fiction novel by Samuel R. Delaney,
only a poet can understand an otherwise indecipherable message from another galaxy.
When it comes to hearing aliens, we may be victims of our assumptions about how they
would talk to us. We tend to think of the radio as the best means of communications
because it was the first such technology that humans invented, says Wright. But with our
most powerful technology, she says, we could theoretically pack all the internet�s contents
into a message sent tens of thousands of light-years away through a laser beam�which means another
civilization could do the same And so Wright and others are developing a
new field of astronomy. It�s called optical SETI, and its instruments are focused on a
different band of the light spectrum than radio astronomy, looking instead at the same
waves our eyes take in, along with infrared frequencies, which are just a smidge longer.
It�s also a technology we suspect aliens might use because humans have found it so
powerful.
Young man taking picture on a crossroad, rear view, Tokyo, Japan
Wright is leading an optical SETI project to build a pair of observatories, faceted
like giant soccer balls, in California. She hopes to turn prototypes on this year and
to be watching the entire sky within six years. They will look for bright bursts of light
as if searching for a superpowered camera flash from an alien photographer.
But like radio astronomy, optical SETI isn�t foolproof. It works only in dark and clear
skies. The technology can also be overly sensitive�optical telescopes are �delicate creatures,� says
Paul Horowitz, a physicist at Harvard who is collaborating with Wright. The way to reduce
false alarms is to use more than one instrument simultaneously. (Apparently, it takes at least
two eyes to spot the alien in the room.) �Multiple observatories,� Horowitz says, �are the
only way to go for these things that go bump in the night and only rarely.�
Then again, it�s entirely possible that extraterrestrials have evolved beyond devices�or
never created them in the first place. Thousands of Planets
On April 8, 2009, NASA�s satellite-based Kepler telescope delivered its first image.
Scientists pointed the instrument at a patch of sky tucked under the wing of the Cygnus
constellation, the swan that flies across the Milky Way. The goal: to find Earth-like
planets. Alone at the NASA Ames Research Center in
Northern California that night, Natalie Batalha, an astrophysicist with the Kepler mission,
watched the first image arrive on her computer monitor. She describes it like a champagne
glass slowly filling with bubbles. When the picture was complete, Batalha saw immediately
that Kepler had delivered a revelatory view of the universe. �It looked like you�d
dumped a bunch of salt on black paper,� she says, still in awe of the picture. �Just
so many stars.� Since that moment, Kepler and other projects
have revealed a new truth about the universe: It is unspeakably rich in planets. The tally
climbs every week or two, with the current total nearing 4,000. This number alone boosts
the hope of finding intelligent life. �When you realize that every pinpoint of light has
a planet,� she says, �you start to see the galaxy differently,� says Batalha. �It
would be foolish not to look.�
This illustration shows NASA's Cassini spacecraft diving through the plume of Saturn's moon
Enceladus, in 2015 JPL-Caltech/NASA This illustration shows NASA's Cassini spacecraft
diving through the plume of Saturn's moon Enceladus, in 2015 JPL-Caltech/NASA
These discoveries have completely reframed the odds behind the search for extraterrestrial
intelligence. Those odds were outlined by Frank Drake, the father of modern SETI. He
calculated the number of civilizations that could be sending us a signal right now by
considering a string of variables: how often life-friendly stars are formed, the proportion
of these that have orbiting planets and the fraction of these planets that are habitable,
among other factors. The larger the numbers for all these components, the higher the chances
of finding E.T. Even if every other variable stays the same, the number of planets we now
know about changes the equation dramatically. Finding extraterrestrial intelligence may
no longer be a question of �if� but rather one of �when.�
So far, we are still waiting. A 72-second signal detected in 1977 generated brief excitement
but was never heard again. Astronomers now think the noise was generated by gas from
a comet. In the 16 years that physicist Gerry Harp has been hunting aliens at the SETI Institute,
he says only one signal has looked promising, but that turned out to be from a satellite.
Likewise, the Green Bank Telescope�s ultra-sensitive receptor found no trace of alien messages
coming from �Oumuamua. Loeb, the Harvard astronomer who led the investigation, says
there�s a chance the telescope could have missed a flickering signal. But the scientists
weren�t surprised by the noiselessness that followed.
Like many who devote their careers to listening for aliens, they are accustomed to radio silence.
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