Thirty years ago today, NASA’s Voyager 1 spacecraft had already traveled well beyond the realm of the planets and was shooting toward interstellar space. Nearly a billion miles farther out than Neptune, it suddenly swiveled around and stared backward. There, pressed onto a star-studded sky, were a dazzling array of planets—ringed Saturn, giant Jupiter, bright white Venus, and a stunningly pale, blue, watery Earth.
On Valentine’s Day in 1990, Voyager methodically assembled a family portrait of the solar system’s many worlds. Carl Sagan had first proposed the observation nearly a decade earlier, only to have the idea rejected over and over again for several reasons, including concerns that the images wouldn’t provide any scientific value. But Voyager was hurtling toward the edge of the solar system, and its cameras were imminently shutting down. From its perch nearly four billion miles away, the spacecraft had one last chance to snap a photo of its home planet.
“Really, this was the last-ever opportunity,” says the Planetary Science Institute’s Candy Hansen, who helped plan the photo sequence. (Now, Hansen is the force behind JunoCam, which is riding aboard NASA’s Juno spacecraft and returning ethereal, gorgeous pictures of Jupiter.)
At the time, Hansen was part of the Voyager imaging team at NASA’s Jet Propulsion Laboratory. Her job, as the experiment representative, included planning the spacecraft’s observations and then checking the resulting images to make sure everything worked as planned—which meant that of the billions of people on Earth, she was the first human to see the image now referred to as the Pale Blue Dot.
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“It was really quite overwhelming to think about,” Hansen recalls. “That our little spacecraft from so far away—that this was a picture of home, and somewhere in that little bright speck, I was sitting at my desk.”
Thirty-four minutes after capturing Earth, Voyager’s cameras turned off forever. In the now-iconic image, a small, unobtrusive pinprick of light hovers amid a ray of scattered sunlight, appearing cosmically inconsequential. The photo’s legacy is that it has inspired the opposite response: a deep recognition of Earth’s importance, its fragility, its uniqueness.
“That’s here. That's home. That's us. On it everyone you love, everyone you know, everyone you ever heard of, every human being who ever was, lived out their lives … on a mote of dust suspended in a sunbeam,” Sagan later wrote in his book, Pale Blue Dot. “In our obscurity, in all this vastness, there is no hint that help will come from elsewhere to save us from ourselves.”
Hansen spoke with National Geographic about what the Pale Blue Dot meant to her then, what it means to her now, and where she’s stashed the original photograph. (This interview has been edited for length and clarity.)
How did you end up being the first human to see the Pale Blue Dot?
I went to work for the Voyager imaging team in 1977, and I started out as the assistant to the assistant experiment representative. The imaging team, who were a bunch of scientists scattered around the country, relied on the experiment rep at JPL to implement everything on their behalf.
My main job was planning for all of our observations and camera commands for the flybys themselves. I had been helping Carl with this observation since its beginning. It was his vision. But as the person on the scene at JPL, it was my job to fill out the form that says, “Here’s the request, here’s what we want to do,” go to the meetings, just do the legwork.
We’d gotten turned down a bunch of times, but then finally in 1989, realizing that really, this was the last-ever opportunity, we got permission to go forward with this observation. So I had been involved in planning the observation as well as ultimately looking at the pictures.
How did you all design the observation?
One of the sequence designers and I sat down and looked at what we could do. Carl’s idea was to mosaic the whole sky and have the whole star background of all of the planets—but we just didn’t have enough space on the tape recorder. So we came up with a picture of every planet, in color, and some stars. We did this kind of hobby-horse-looking thing that connected all the planets with wide-angle images, and then we did the images of the sun.
And then, finally, the pictures started to hit the ground.
So you were checking the images and making sure the observations had worked.
Yes. And because it was first in, first out on the tape recorder, and we had started out at Neptune, we were working our way in. I was looking first at the Neptune images, and it was like, Oh yeah, OK, there’s Neptune, and then Uranus—oh yeah, there’s Uranus, and then Saturn, and then Jupiter—and those are relatively large planets, so they were relatively large little spots.
I could recognize almost immediately the blemishes and the specks of dust that are in every image, so I could pretty quickly pull up an image and identify “Blemish, blemish, dust, ah, there’s Neptune,” and I was just very systematically working my way in.
And when I got to the picture that should have had the Earth in it, I didn’t see it at first.
I checked the other two filters, and I was like, How could we have missed the Earth? We got all these other planets, and our whole idea was to capture the Earth! That was a moment of terror, panic, that something had—after all these years when we finally had this opportunity—that something had gotten screwed up.
So I’m sitting there thinking, What are we going to do? What are we going to say? And then I noticed, Oh wait, over in this ray of scattered light, there’s a bright spot that I don’t recognize as dust or a blemish. So I thought, OK, let me get the other two filters. Sure enough, it was in all three images, and I knew positively it wasn’t an artifact or anything else because I knew how to recognize those.
It was the Earth.
I just sat there. It was, honestly, it was really quite overwhelming to think about. That our little spacecraft was so far away, that this was a picture of home, and somewhere in that little bright speck, I was sitting at my desk. And it was so dramatic with it being in that ray of scattered light.
Logically, I knew this was just scattered light in the optics. I knew that. But my heart was like, Oh it looks so special. The sun is shining on us! So then after I composed myself, I started making calls to let people know that we had gotten it, it looked good, all three colors, and then everything else happened after that.
Did you know that you were looking at an image that would have such an impact?
I felt it, yeah. I always did. I’d had to, in a sense, sell the observation. So I had definitely given it some thought. But giving it some thought and the actual emotional impact are two different things.
In coming back to it now, I’ve really come to realize how timeless that image is. When we took it in 1990, the Cold War was still going on. It was still the Soviet Union and the United States with nuclear warheads pointed at each other. So the message at that point in time was, Let’s not screw up the home planet by nuking each other.
And today, it’s still every bit as relevant. Let’s not screw up our home world by cooking our atmosphere—climate change. In that regard, it’s really timeless. It’s the sense that we only have one home. Mars is really not that hospitable. And neither is the moon. We have one home world, and we really do need to take care of it.
I think people kind of know that conceptually, but actually seeing Earth—and I’m thinking about Earthrise as well—seeing the planet as a whole seems to really drive that point home in an emotional way.
Yes. And that image, Earthrise, oh my god it is incredibly important to how we see ourselves.
When you look at the Pale Blue Dot today, do you still have the same kinds of reactions that you did when you first saw it?
Yes. I still get chills down my back. It’s that whole, a picture is worth a thousand words—well maybe that particular one is worth a million.
We put up the images in JPL’s von Kármán auditorium, and they took up a whole stretch of wall space, and they were just sort of mounted, the wide angles connecting together, and then the narrow angles of the planets themselves. And the person who was in charge of that, he told me one time that he always had to replace the picture of Earth, because people would come up and they would touch it. Isn’t that cool? That’s where we live!
I wonder how many images of Earth he had to replace.
I don’t know! Wouldn’t that be fun to find out?
Or where all of the originals are.
Oh those, I can tell you. They’re in a box in my closet.
Are you serious?
Yeah, I am. Not the digital data, of course, that’s in the archive. But all those original hard copies that we pinned up, that we had laying around, those are all in a box in my closet.