Just as families record the changing faces of their kids as they grow older, the Hubble Space Telescope each year captures the changing faces of the solar system’s four colorful gas-giant planets.
The newest photo in that yearbook is a portrait of Jupiter taken June 27 that reveals clouds swirling in the planet’s turbulent atmosphere that are painted with a color palette more intense than seen in previous years.
Mike Wong, an associate researcher in UC Berkeley’s Department of Astronomy and one of three members of the Hubble team taking the photos, was most intrigued by a mysterious color change around Jupiter’s equator: The formerly white equatorial belt has become orangish. And, surprisingly, Red Spot Jr., a planet that was red the last time it was photographed, has turned white. It is now back to the way it looked at its formation in 2000, before it flipped to red in 2006.
No one quite knows why the shifts occurred, but the annual portraits are a way to catalog such changes so that scientists can understand the physics and chemistry underlying the formation and motions of clouds and storms in the planets’ atmospheres.
"The goal is to fill in gaps in the archive of Jupiter, Saturn, Uranus and Neptune images because, some years, there were no successful proposals to use Hubble to observe individual planets," Wong said. "Now we at last have yearly data sets, and the number of new papers based on the yearly data is roughly doubling every year, providing a really good resource for all sorts of different science investigations."
Wong and his colleagues analyzed yearbook photos of Uranus and Neptune in February and are anticipating new images of Saturn and Neptune later this year.
The images are taken in visible light as part of the Outer Planets Atmospheres Legacy (OPAL) program, which is run by Amy Simons of Goddard Space Flight Center in Maryland, with the assistance of Wong and Glenn Orton of the Jet Propulsion Laboratory in California.
For explanations of various features on Jupiter, including the Great Red Spot and Red Spot Jr., link to the Space Telescope Science Institute’s story below.