Image above: Composite image of Jupiter Image credit: X-ray: NASA/CXC/SwRI/ R. Gladstone et al.; Optical: NASA/ESA/Boston Univ./J.Clarke & Hubble Heritage (AURA/STScI) Image credit: X-ray: NASA/CXC/SwRI/ R. Gladstone et al.; Optical: NASA/ESA/Boston Univ./J.Clarke & Hubble Heritage (AURA/STScI)

On February 28, 2007, NASA's New Horizons spacecraft made its closest approach to Jupiter on its ultimate journey to Pluto. This flyby gave scientists a unique opportunity to study Jupiter using the package of instruments available on New Horizons, while coordinating observations from both space- and ground-based telescopes including NASA's Chandra X-ray Observatory.

In preparation for New Horizon's approach of Jupiter, Chandra took 5-hour exposures of Jupiter on February 8, 10, and 24th. In this new composite image, data from those separate Chandra's observations were combined, and then superimposed on the latest image of Jupiter from the Hubble Space Telescope.

The purpose of the Chandra observations is to study the powerful X-ray aurorae observed near the poles of Jupiter. These are thought to be caused by the interaction of sulfur and oxygen ions in the outer regions of the Jovian magnetic field with particles flowing away from the Sun in the so-called solar wind. Scientists would like to better understand the details of this process, which produces aurorae up to a thousand times more powerful than similar aurorae seen on Earth.