Recent JunoCam Revelations About Discrete Features in Jupiter’s Atmosphere

<p>JunoCam, the visible imager on the Juno mission&#8217;s payload that was designed primarily for public-outreach purposes, continues to produce images of Jupiter that provide unexpected scientific benefits.&#160; Juno&#8217;s polar orbits enable observing regions of the planet that have not previously been detected at such high resolution by any previous spacecraft. JunoCam has a single CCD detector with an integral color-strip filter that enables the instrument to image in four color bands&#8212;blue, green, red and an 889-nm methane band.&#160; JunoCam maps a field of view of 58&#176; across the width of the detector, perpendicular to the spacecraft scan direction. We will describe characteristics and likely origins of bright white compact (~50 km) clouds, informally dubbed &#8220;pop-up&#8221; clouds by the JunoCam team.&#160; We used the length of shadows of these and other features to determine the relative heights of clouds and assigned a provisional chemical classification based on relative altitudes from equilibrium-chemistry predictions. We tracked the continued interactions of small anticyclonic ovals with Jupiter&#8217;s Great Red Spot (GRS) that drew off high-altitude reddish haze into strips (commonly called &#8220;flakes&#8221;) on its western edge.&#160; A lightning flash was detected in one of the compact circumpolar cyclones in late December. Observations of the south-polar circumpolar cyclones showed that the original unequally sided pentagon becoming a hexagon &#8211; with a cyclone filling in an open area, then a pentagon again over the course of 110 days.&#160; In a collaboration with amateur astronomer Clyde Foster (S. Africa), we observed the morphology of an unexpected upwelling in late May of 2020, now known as &#8220;Clyde&#8217;s Spot&#8221;, and tracked its evolution in concert with several ground-based observations.&#160; We also measured ~40-50 m/s winds around the sinuous jet bounding the South Polar Hood, an upper-level haze generated by auroral-related chemistry.&#160; Lightly processed and raw JunoCam data continue to be posted on the JunoCam webpage at https://missionjuno.swri.edu/junocam/processing.&#160;&#160; Citizen scientists download these images and upload their processed contributions.</p>