Europa helps astronomers penetrate Jupiter’s lost belt

Scientist have been able to see what’s going on inside Jupiter for the first time by utilising its moon Europa – Deskarati

The ongoing turmoil inside Jupiter’s missing – and slowly re-emerging – South Equatorial Belt can now be seen in unprecedented detail thanks to the Keck II telescope’s Adaptive Optics system and the cooperation of the icy Jovian moon Europa. In this newly released Keck image, the gas giant is shown as it looks in thermal infrared (IR) light, at a wavelength of nearly 5 microns (shown in bright red and yellow), overlaid on a composite image of three shorter, near infrared bands (1.21, 1.58 and 1.65 microns).

“The thermal IR senses breaks in the cloud cover,” said astronomer Mike Wong of the University of California at Berkeley. The thermal IR data is essentially showing heat from Jupiter’s interior being radiated into space. The three other IR bands, in contrast, are reflected sunlight. Put them all together and compare them to visible light images and scientists get a picture of a thinning, breaking layer of high, bright, icy clouds that have obscured the brown-red South Equatorial Belt (SEB) for about a year, making it look like a wide white zone.

“We see wispy cloud-free regions at 5 microns in the SEB,” said Wong, “But they are much less extensive than the near-infrared dark regions surrounding them. The data show that the change from zone-like to belt-like appearance is a complex process that takes place at different speeds in each layer of Jupiter’s atmosphere.”

The four-band infrared image was created using a clever twist on the Keck II Telescope’s Adaptive Optics, which effectively cancels out much of the interference of Earth’s atmosphere. Normally astronomers use a powerful laser to create an artificial guide star. With that they can monitor Earth’s constantly changing atmosphere and cancel out the distortions at a rate of up to 2,000 times per second.

But Jupiter is so bright that it hides the laser guide star. The astronomers needed something much brighter that was also very close to Jupiter in the sky. On November 30, 2010, the icy Jovian moon Europa was positioned just right to serve that purpose, explained Franck Marchis, also of UC Berkeley and the SETI Institute.

via Europa helps astronomers penetrate Jupiter’s lost belt.

This entry was posted in Cosmology. Bookmark the permalink.