One year ago NASA’s Juno spacecraft arrived at Jupiter., and it has sent back wonderful photos via the JunoCam. As NASA put’s it: The scientific themes of the Juno mission are to study the interior, atmosphere, and magnetosphere of Jupiter (Bolton et al., this issue). The spacecraft has been highly optimized for the operation of its seven science instruments, leading to a solar-powered, sun-pointing, spinning design.
Such a platform presents challenges for imaging, both from motion blur and pointing geometry. But it was appreciated that visible imaging is an important component of public engagement for any mission. So a visible camera, Junocam, was included primarily for education and public outreach (EPO), funded from the mission’s EPO budget and given a fairly constrained allocation of spacecraft mass resources. Despite the challenges, Juno’s polar orbit offers a unique vantage.
The Expected Science Return is High. NASA says: Junocam takes advantage of Juno’s unique polar orbit, its extremely low-altitude perijove, and its complementary suite of instruments that probe the interior and atmosphere. The orbit enables one to study the atmospheric dynamics, the clouds, and the aurora right up to the pole, which no spacecraft has ever done before. The orbit also enables one to study the equatorial clouds and winds “up close,” with a spatial scale of 3 km per pixel at perijove.
Finally, Junocam provides “eyes” in visible light for three other instruments, the microwave radiometer (MWR), which peers through the clouds down to 100 bar levels (Janssen et al. 2014), the ultraviolet imaging spectrograph (UVS), which studies UV auroral emissions in the polar magnetosphere (Gladstone et al. 2014), and the Jovian infrared auroral mapper (JIRAM), which studies IR auroral emissions and the IR emissions emanating from the clouds at all latitudes (Adriani et al. 2014).