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
September 22, 2014 -- Updated 1259 GMT (2059 HKT)
You could be forgiven for thinking no one cares -- or even should care, right now -- about climate change, writes CNN's John Sutter. But you'd be mistaken.
September 21, 2014 -- Updated 2132 GMT (0532 HKT)
David Gergen says the White House's war against ISIS is getting off to a rough start and needs to be set right
September 22, 2014 -- Updated 1300 GMT (2100 HKT)
John Sutter boarded a leaky oyster boat in Connecticut with a captain who can't swim as he set off to get world leaders to act on climate change
September 22, 2014 -- Updated 1917 GMT (0317 HKT)
Ruben Navarrette says making rude use of the Mexican flag on Mexican independence day in a concert in Mexico was extremely tasteless, but not an international incident.
September 22, 2014 -- Updated 1359 GMT (2159 HKT)
Michael Dunn is going to stand trial again after a jury was unable to reach a verdict; Mark O'Mara hopes for a fair trial.
September 19, 2014 -- Updated 2322 GMT (0722 HKT)
Is ballet dying? CNN spoke with Isabella Boylston, a principal dancer at the American Ballet Theatre, about the future of the art form.
September 19, 2014 -- Updated 2147 GMT (0547 HKT)
Sally Kohn says it's time we take climate change as seriously as we do warfare in the Middle East
September 22, 2014 -- Updated 1927 GMT (0327 HKT)
Laurence Steinberg says the high obesity rate among young children is worrisome for a host of reasons
September 19, 2014 -- Updated 1302 GMT (2102 HKT)
Dean Obeidallah says an Oklahoma state representative's hateful remarks were rightfully condemned by religious leaders..
September 19, 2014 -- Updated 1922 GMT (0322 HKT)
No matter how much planning has gone into U.S. military plans to counter the Islamic State in Iraq and Syria, the Arab public isn't convinced that anything will change, says Geneive Abdo
September 19, 2014 -- Updated 1544 GMT (2344 HKT)
President Obama's strategy for destroying ISIS seems to depend on a volley of air strikes. That won't be enough, says Haider Mullick.
September 19, 2014 -- Updated 1303 GMT (2103 HKT)
Paul Begala says Hillary Clinton has plenty of good reasons not to jump into the 2016 race now
September 19, 2014 -- Updated 1501 GMT (2301 HKT)
Scotland decided to trust its 16-year-olds to vote in the biggest question in its history. Americans, in contrast, don't even trust theirs to help pick the county sheriff. Who's right?
September 19, 2014 -- Updated 0157 GMT (0957 HKT)
Ruben Navarrette says spanking is an acceptable form of disciplining a child, as long as you follow the rules.
September 19, 2014 -- Updated 1547 GMT (2347 HKT)
Frida Ghitis says the foiled Australian plot shows ISIS is working diligently to taunt the U.S. and its allies.
September 19, 2014 -- Updated 1958 GMT (0358 HKT)
Young U.S. voters by and large just do not see the midterm elections offering legitimate choices because, in their eyes, Congress has proven to be largely ineffectual, and worse uncaring, argues John Della Volpe
September 19, 2014 -- Updated 0158 GMT (0958 HKT)
Steven Holmes says spanking, a practice that is ingrained in our culture, accomplishes nothing positive and causes harm.
September 18, 2014 -- Updated 1831 GMT (0231 HKT)
Sally Kohn says America tried "Cowboy Adventurism" as a foreign policy strategy; it failed. So why try it again?
September 18, 2014 -- Updated 1427 GMT (2227 HKT)
Van Jones says the video of John Crawford III, who was shot by a police officer in Walmart, should be released.
September 18, 2014 -- Updated 1448 GMT (2248 HKT)
NASA will need to embrace new entrants and promote a lot more competition in future, argues Newt Gingrich.
September 16, 2014 -- Updated 2315 GMT (0715 HKT)
If U.S. wants to see real change in Iraq and Syria, it will have to empower moderate forces, says Fouad Siniora.
September 18, 2014 -- Updated 0034 GMT (0834 HKT)
Mark O'Mara says there are basic rules to follow when interacting with law enforcement: respect their authority.
September 16, 2014 -- Updated 1305 GMT (2105 HKT)
LZ Granderson says Congress has rebuked the NFL on domestic violence issue, but why not a federal judge?
September 16, 2014 -- Updated 1149 GMT (1949 HKT)
Mel Robbins says the only person you can legally hit in the United States is a child. That's wrong.
September 15, 2014 -- Updated 1723 GMT (0123 HKT)
Eric Liu says seeing many friends fight so hard for same-sex marriage rights made him appreciate marriage.
ADVERTISEMENT