Voyager Snaps a ‘Family Photo’ of Solar System

The intrepid Voyager 1 spacecraft has sent back its final series of photos from space, capturing the planets of the solar system just as they were intended to be--insignificant points of light in a cold, dark universe.

“This is where we live,” astronomer Carl Sagan said as he pointed at one small speck of light. “On a blue dot.”

The historic “family photo” of the solar system was released Wednesday by the National Aeronautics and Space Administration, but it may prove disappointing to those who had expected to see a single image of the entire system. The planets are so widespread that Voyager had to take 60 different pictures, which engineers at the Jet Propulsion Laboratory used to create a “mosaic” of the solar system.

“This was Voyager’s last light,” project scientist Edward Stone said at a press conference in Washington. Its camera is now off, and no one expects it to be turned on again.

Stone said the montage represents the first photo ever taken of the solar system, and it marks the last opportunity to take such a photo “for several decades.”

Voyager 1 is now speeding toward outer space, making it possible for it to take one last look over its shoulder as it “plunges into the interstellar dark,” as Sagan put it. The next generation of spacecraft will be designed to orbit other planets, rather than venture out into deep space, so no other craft--even those on the distant drawing boards--will be able to do what Voyager did in the final chapter of its life.

If all goes well, the small spacecraft will be able to radio back scientific data from the outer solar system for up to 25 years, Stone said, but its camera will remain dark.

Wednesday marked the end of a long trail for Sagan, who has been arguing for nearly a decade in favor of at least attempting to take a “family portrait” of Earth and its nearest neighbors. Some NASA officials feared the project might cost too much and produce too little, but Sagan believes that humans deserve to see the Earth for what it is, a strangely vulnerable speck indistinguishable from billions of other points of light, but the only one known to support life.

Sagan described his feelings Wednesday, as he looked at the product of his long quest, as “humbling.”

Every human drama that has ever been acted out took place on that one, blue speck, he observed.

“That’s where everybody lived,” he said. “It’s a very small stage on the great cosmic arena.”

Voyager actually shot the photos last Feb. 13, but other pressing demands for NASA’s tracking and communications system prevented the data from being transmitted back to Earth until mid-March. Voyager is about 4 billion miles away, so it took the signals 5 1/2 hours to reach Earth.

Stone estimated that the photos cost “around $200,000,” because some phases of the Voyager program had to remain active longer than had been anticipated in order to complete the project.

But staying around longer than had been expected is nothing new for Voyager. The twin spacecraft (Voyagers 1 and 2) had been designed to visit two planets, Jupiter and Saturn. But Voyager 1’s lifetime was extended and it was sent on to explore two more planets, Uranus and Neptune.

Coupled with earlier robotic missions, the spacecraft brought about a revolution in the understanding of the solar system, Stone said.

Asked how he would revise a 1975 encyclopedic description of the sun and its planets, Sagan said that “you would simply tear it up and start from scratch.”

In all, the two spacecraft visited four planets and sailed past 56 moons, many of which the Voyagers discovered. They taught scientists that the planets are full of surprises, and that the moons, which many had expected to be rather dull, were in many cases vibrant bodies with powerful geological forces.

They discovered the hot volcanoes of Jupiter’s Io, the most active moon in the sun’s family, as well as the icy volcanoes of Neptune’s Triton, which turned out to be the coldest body in the solar system.

And they aren’t through yet.

“The Voyager expedition is not yet over,” Stone said. The two craft will continue to study the million-mile-an-hour solar wind and, later, the rarefied gases of the interstellar medium.