WASHINGTON Jupiter is changing its stripes, perhaps because its seasons are changing, scientists reported on Thursday.
The orbiting Hubble Space Telescope is capturing some of the most dramatic atmospheric changes ever documented, the team at NASA and the Space Telescope Science Institute in Baltimore reported.
White areas of the planet's cloud bands are turning brown and brownish areas are lightening up, the researchers said.
"It does this every once in a while," planetary scientist Amy Simon-Miller of the NASA Goddard Space Flight Center said in a telephone interview.
"Jupiter doesn't stay the same color all the time. We are just lucky -- it is going through what we call a global upheaval, meaning the belts and bands are changing color at the same time."
The changes, described in detail at hubblesite.org/news/2007/25, might be due to seasonal effects, Simon-Miller said.
"Jupiter's year is much longer than an Earth year -- it's 12 years," she said.
Changes in the heat from the sun may be affecting the gas giant's atmosphere, she said. As planets orbit, their angle from the sun varies, changing how directly the sun's rays hit and in turn causing the seasons.