Skip to main content

If 'E.T.' finds Voyager 1, will it phone Earth?

By Meg Urry, Special to CNN
September 23, 2013 -- Updated 1753 GMT (0153 HKT)
As NASA scientists report that Voyager 1 has left the solar system, take a look at some of the amazing images the probe has provided its earthbound audience. As NASA scientists report that Voyager 1 has left the solar system, take a look at some of the amazing images the probe has provided its earthbound audience.
HIDE CAPTION
What Voyager saw
What Voyager saw
What Voyager saw
What Voyager saw
What Voyager saw
What Voyager saw
What Voyager saw
What Voyager saw
What Voyager saw
What Voyager saw
What Voyager saw
What Voyager saw
What Voyager saw
What Voyager saw
<<
<
1
2
3
4
5
6
7
8
9
10
11
12
13
14
>
>>
STORY HIGHLIGHTS
  • NASA's Voyager 1 spacecraft left the solar system and entered interstellar space
  • Meg Urry: Voyager's achievement is a major milestone in human exploration
  • She says the mission, launched 36 years ago, will go forth unimpeded for millenniums
  • Urry: There are no expectations that it will encounter other civilizations, but possibility exists

Editor's note: Meg Urry is the Israel Munson professor of physics and astronomy at Yale University and director of the Yale Center for Astronomy and Astrophysics.

(CNN) -- In 1519, Portuguese explorer Ferdinand Magellan launched the expedition that completed the first circumnavigation of the globe. And so humanity learned the full extent of its world.

This week, we learned from Science magazine that NASA's Voyager 1 spacecraft -- currently the man-made object farthest from Earth -- crossed a boundary of the solar system and entered interstellar space sometime last summer.

Like Magellan's voyage, Voyager's achievement is a major milestone in human exploration. In a remarkably short time by cosmic standards (the universe being 13.7 billion years old), humans have evolved to the point of sending robotic diplomatic missions to other planets and stars.

This particular emissary from the human race carries a recording of greetings in 55 languages as well as images explaining who we are. Although the Voyager scientists had no particular expectation of encountering other civilizations, they knew the mission would go forth unimpeded for millenniums. So they prepared a message for any distant future being who might stumble across this man-made artifact.

Meg Urry
Meg Urry

If "E.T." finds Voyager 1, will it phone home? We know that planets around other stars ("exoplanets") are abundant, and that when liquid water and carbon-based compounds and an energy source are present even in the most inhospitable zones on the Earth, life arises easily. But the kind of intelligent life that can build and launch a pioneering spacecraft is surely much more rare. And if someone answers the call, it will be sufficiently far in the future that the Earth-bound world as we know it will have changed beyond recognition.

Unlike missions to nearby Mars or Venus, Voyager 1 and 2 (both spacecraft were launched in 1977) and their older siblings, Pioneer 10 and 11 (launched in 1972 and 1973, respectively) headed for outer space from the beginning. They visited Jupiter, Saturn, Uranus and Neptune, taking photographs of unprecedented clarity and making complex measurements of the particles and magnetic fields around the planets.

Voyager 1 is the fastest-moving and most distant of the four spacecraft. Data collected by its remaining instruments have been interpreted by scientists as indicating a crossing of the boundary between our solar system and interstellar ("between the stars") space. It's not a sharp boundary, and there are definitely no signposts, so there has been some debate about the exact moment of transition.

NASA: Voyager 1 has left solar system
Where no man-made object has gone before

In fact, the exact date doesn't matter. Whether it was July 2012 or August 2012 or even months earlier or later, humans have unquestionably projected their presence well beyond any previous location.

It's a bit different from Magellan's voyage, however. In those ancient days, travel was the only way to investigate the world. Today we survey our world -- and a large fraction of the observable universe -- using powerful telescopes, on the ground and in space.

Very deep exposures taken with the Hubble Space Telescope have revealed that the Milky Way galaxy is but one of a trillion galaxies in the observable universe.

There are hundreds of billions of stars in the Milky Way galaxy alone, each of which could have a system of planets orbiting around it. Some of these are likely to harbor life, albeit of a primitive form.

In terms of knowing our 21st-century world, NASA's robotic scientific satellites have made huge advances. And from the ground, telescopes study exoplanets and the SETI Institute searches for extraterrestrial intelligence using a large radio telescope array in California. In terms of receiving signals, Earth-bound and near-Earth telescopes are unsurpassed.

In terms of outward communication, TV signals created decades ago have long since announced our presence -- in fact, because such signals travel at the speed of light, they left the solar system only days after the initial broadcast.

But in terms of pieces of metal human hands have touched, Voyager 1 is unique. Now some 36 years and a few days after it was launched into space, more than 11 billion miles from the sun, traveling at 38,000 mph, Voyager 1 will doubtless travel onward for tens of thousands of years to come.

Its power source won't last nearly that long. Voyager 1 has sufficient power for remaining instruments through at least 2020, and if some are turned off to conserve power, a single instrument could last another five years afterward. But then the "little spacecraft that could" will go silent.

Forty thousand years from now, after traversing 10 trillion miles or so of interstellar space, Voyager 1 will approach the then-closest star, AC +79 3888. At that point it will be a ghost ship, representing an old civilization, gone but enshrined forever in the golden record.

As John Grunsfeld, NASA's associate administrator for science in Washington, said, "Perhaps some future deep space explorers will catch up with Voyager, our first interstellar envoy, and reflect on how this intrepid spacecraft helped enable their journey."

Follow us on Twitter @CNNOpinion.

Join us on Facebook/CNNOpinion.

The opinions expressed in this commentary are solely those of Meg Urry.

ADVERTISEMENT
Part of complete coverage on
August 19, 2014 -- Updated 2203 GMT (0603 HKT)
It used to be billy clubs, fire hoses and snarling German shepherds. Now it's armored personnel carriers and flash-bang grenades, writes Kara Dansky.
August 20, 2014 -- Updated 1727 GMT (0127 HKT)
Maria Haberfeld: People who are unfamiliar with police work can reasonably ask, why was an unarmed man shot so many times, and why was deadly force used at all?
August 18, 2014 -- Updated 2152 GMT (0552 HKT)
Ruben Navarrette notes that this fall, minority students will outnumber white students at America's public schools.
August 19, 2014 -- Updated 2121 GMT (0521 HKT)
Humans have driven to extinction four marine mammal species in modern times. As you read this, we are on the brink of losing the fifth, write three experts.
August 19, 2014 -- Updated 1158 GMT (1958 HKT)
It's been ten days since Michael Brown was killed, and his family is still waiting for information from investigators about what happened to their young man, writes Mel Robbins
August 21, 2014 -- Updated 1411 GMT (2211 HKT)
Sally Kohn says the Ferguson protests reflect broader patterns of racial injustice across the country, from chronic police violence and abuse against black men to the persistent economic and social exclusion of communities of color.
August 18, 2014 -- Updated 1242 GMT (2042 HKT)
The former U.K. prime minister and current U.N. envoy says there are 500 days left to fulfill the Millennium Goals' promise to children.
August 18, 2014 -- Updated 1310 GMT (2110 HKT)
Julian Zelizer says the left mistrusts Clinton but there are ways she can win support from liberals in 2016
August 20, 2014 -- Updated 1738 GMT (0138 HKT)
Peter Bergen says the terror group is a huge threat in Iraq but only a potential one in the U.S.
August 16, 2014 -- Updated 1734 GMT (0134 HKT)
Mark O'Mara says the way cops, media, politicians and protesters have behaved since Michael Brown's shooting shows not all the right people have learned the right lessons
August 17, 2014 -- Updated 1523 GMT (2323 HKT)
Retired Lt. Gen. Mark Hertling says the American military advisers in Iraq are sizing up what needs to be done and recommending accordingly
August 15, 2014 -- Updated 1941 GMT (0341 HKT)
Marc Lamont Hill says the President's comments on the Michael Brown shooting ignored its racial implications
August 15, 2014 -- Updated 2146 GMT (0546 HKT)
Joe Stork says the catastrophe in northern Iraq continues, even though many religious minorities have fled to safety: ISIS forces -- intent on purging them -- still control the area where they lived
August 14, 2014 -- Updated 2226 GMT (0626 HKT)
Tim Lynch says Pentagon's policy of doling out military weapons to police forces is misguided and dangerous.
August 15, 2014 -- Updated 1315 GMT (2115 HKT)
S.E. Cupp says millennials want big ideas and rapid change; she talks to one of their number who serves in Congress
August 14, 2014 -- Updated 2357 GMT (0757 HKT)
Dorothy Brown says the power structure is dominated by whites in a town that is 68% black. Elected officials who sat by silently as chaos erupted after Michael Brown shooting should be voted out of office
August 14, 2014 -- Updated 1149 GMT (1949 HKT)
Bill Schmitz says the media and other adults should never explain suicide as a means of escaping pain. Robin Williams' tragic death offers a chance to educate about prevention
August 15, 2014 -- Updated 1505 GMT (2305 HKT)
Nafees Syed says President Obama should renew the quest to eliminate bias in the criminal justice system
August 14, 2014 -- Updated 2024 GMT (0424 HKT)
Eric Liu says what's unfolded in the Missouri town is a shocking violation of American constitutional rights and should be a wake-up call to all
August 13, 2014 -- Updated 1922 GMT (0322 HKT)
Neal Gabler says Lauren Bacall, a talent in her own right, will be defined by her marriage with the great actor Humphrey Bogart
August 15, 2014 -- Updated 1056 GMT (1856 HKT)
Bob Butler says the arrest of two journalists covering the Ferguson story is alarming
August 13, 2014 -- Updated 2035 GMT (0435 HKT)
Mark O'Mara says we all need to work together to make sure the tension between police and African-Americans doesn't result in more tragedies
August 18, 2014 -- Updated 2006 GMT (0406 HKT)
Pepper Schwartz asks why young women are so entranced with Kardashian, who's putting together a 352-page book of selfies
August 13, 2014 -- Updated 2308 GMT (0708 HKT)
Michael Friedman says depression does not discriminate, cannot be bargained with and shows no mercy.
August 12, 2014 -- Updated 1525 GMT (2325 HKT)
LZ Granderson says we must not surrender to apathy about the injustice faced by African Americans
ADVERTISEMENT