Art meets astronomy: the JunoCam experiment

A unique citizen-science project associated with NASA’s Jupiter-orbiting Juno mission has produced dazzling images of the giant planet, ranging from stunning views of the filigreed edges of its polar storms to close-ups of the Great Red Spot. Some even transcend realism to become high art.

The project uses an instrument called JunoCam, which was put on the spacecraft largely to reach out to the public and share the excitement of space exploration, according to Candice Hansen, of the Planetary Science Institute in Tucson, Arizona, US, and one of JunoCam’s principal investigators.

But that doesn’t mean the instrument was an afterthought, even though the Juno mission’s primary objectives, which involve measuring Jupiter’s radiation belts and using microwave and gravity sensors to map its internal structure, didn’t require a camera. There were parts of Jupiter near its poles that had never before been imaged, because they aren’t at the right angle to be seen by the Hubble Space Telescope. “The team and myself couldn’t imaging going over the poles and not seeing what they looked like,” says Scott Bolton, the mission’s principal investigator. “We all wanted that poster in our room.”

Technically, the camera has a resolution of about 15 kilometres per pixel at the distances involved in Juno’s once-every-53-days close flybys. That’s not great by the standards of spacecraft currently orbiting the Moon and Mars, but JunoCam also has a 58-degree field of view. That makes it just right for what the scientists wanted.

“If you were close to Jupiter, your eyes would take in a great view,” Bolton says.

But if you tried to look through binoculars, “you would look at only one spot. You lose your ability to see the context.”

Where exactly JunoCam should look, however, isn’t determined by the scientists. Instead, it’s driven by what Hansen calls a “citizen science experiment”.

Using the JunoCam website, amateur astronomers were encouraged to recommend parts of Jupiter at which the camera should be pointed. Then they voted on which they thought were most important. Raw images were posted on the JunoCam website, where people were invited to download them, process them to their hearts’ content, and upload the processed images.

The results are stunning. Some, Hansen says, reveal never-before-suspected features, such as “pop-up storms” that produce scattered white cloud-tops. “We initially called them thunderstorms, but there is no lightning,” she says. “We need a different name until we know what they are.”

Others highlighted chaotic storm patterns near Juniper’s north pole. “This is either a dynamicist’s dream or nightmare,” Hansen says. “I’m not sure which, but we love it.”

Meanwhile, large numbers of citizen scientists are doing their bit. “We have thousands of pictures,” Hansen says.