Jupiter Looks, Um, Different
New images of the planet allow astronomers to peer deeper into its stormy atmosphere.
For his high-school science-fair project, Glenn Orton chose to research Jupiter. It was 1965, and as the United States rushed toward the moon, Orton was mesmerized by the faraway planet, which he could see with his own telescope. He supplemented his project—which ended up winning the top prize—with images of Jupiter that he took himself.
Decades later, Orton, now a scientist at NASA’s Jet Propulsion Laboratory who studies Jupiter, still gets a thrill from looking at pictures of the planet, he told me recently. It helps that they keep getting better. Just look at the one at the top of this article.
This view of Jupiter is quite the departure from the depiction many of us remember from science class, of the planet as a smooth marble with Creamsicle-colored bands and that signature stormy spot. The observations that gave us that classic image only skimmed the cloud tops. But this latest effort to observe Jupiter, which has produced one of the highest-resolution shots yet, dives deeper into the atmosphere, providing a view of the planet that makes it appear to be ablaze.
“This is a wavelength that our eyes don’t see,” says Candy Hansen, a planetary scientist who works on a spacecraft mission to Jupiter, “and, wow, don’t you wish we could?”
The image comes from a telescope at the Gemini Observatory, perched atop a dormant volcano in Hawaii, that performs infrared scans of the cosmos. Though its exterior is frigid, Jupiter is a toasty planet, and infrared light is well suited for capturing the heat coming from deep inside its atmosphere. In this image, regions that appear dark are covered in cold, dense clouds, too thick for the warmth to escape into space. Where the clouds are thin, the heat shines through.
The Gemini picture helps answer a long-standing question about Jupiter’s Great Red Spot, a gargantuan storm that has been churning for centuries: Where do its bright colors come from? Scientists had suspected that the mix of orange and red hues had something to do with the chemical composition of Jupiter’s outer atmosphere, but the new image reveals otherwise. Regions that are dark in visible light appear bright in infrared, which means that the Great Red Spot’s deepest colors are actually holes in the cloud cover, windows into the warm depths of the planet.
Regardless of the type of image, no still portrait can capture the complexities of our solar system’s biggest planet. The forecast on Jupiter is always stormy, which means its clouds are always moving, shifting into new currents and eddies. Even the Great Red Spot, seemingly immutable from our perspective, stretches and shrinks. “There’s not a single static feature anywhere in that image,” says Tim Dowling, a scientist at the University of Louisville who studies planetary atmospheres. “They’re all swirling.”
While the Gemini image adds to the scientific knowledge of Jupiter, much about the planet remains a mystery. Scientists aren’t sure what lies at the heart of the planet—probably a mass of liquid hydrogen and helium, but they can’t be certain. Nor do they understand what drives cyclones at the planet’s poles, which arrange themselves into intricate whirls, like roses in a tight bouquet, without spilling into one another. Scientists once sent a spacecraft—the Galileo probe—plunging through Jupiter’s atmosphere in search of answers in the depths. But in a cruel twist of chance, Galileo fell through a gap in the clouds, an unlucky break that still makes astronomers wince when they think about it.
Each time astronomers release new images of Jupiter, I’m reminded of some early depictions of the planet, made by the French artist Étienne Léopold Trouvelot in the 1880s. Trouvelot created thousands of astronomical drawings, fascinated by what he saw through his telescope. At the time, Jupiter looked like little more than a fuzzy ball through his lens.
In Trouvelot’s drawings, Jupiter’s features are rendered in clean lines and simple colors, appearing almost cartoonish. It’s a little thrilling to look at the illustration now and consider just how much wonder was lying beneath the surface, waiting to be seen.
