The mostly unknown Callisto’s H corona is created by a global tenuous H2 atmosphere and not by surface water as previously believed, providing the first evidence for H2 in Callisto’s atmosphere.
Jupiter
Europa’s Plate Tectonic Activity Is Unlike Earth’s
The moon of Jupiter has likely experienced intermittent, regional plate tectonic activity in the past, although the plates are currently dormant.
Could Jupiter’s Heat Waves Help Solve a Planetary Energy Crisis?
Infrared observations reveal that Jupiter’s upper atmosphere is much warmer than models predict. The discovery may be a clue to finding missing heat sources in other giant planets.
Impact Crater off the African Coast May Be Linked to Chicxulub
The underwater crater, spotted serendipitously in commercial observations of seafloor sediments, is believed to have formed at roughly the same time as the famous Cretaceous-Paleogene impact event.
Meteoric Ions Influence Conductance in the Jovian Ionosphere
Meteoric ions dominate the Jovian lower ionosphere due to their long lifetimes. Due to the large densities of the meteoric ions, conductance is enhanced independently of local time.
A Transition Zone Below Jupiter’s Clouds
The microwave radiometer aboard NASA’s Juno spacecraft reveals the hidden atmospheric circulations at work deep below Jupiter’s colorful clouds.
Could Low-Altitude Reconnection Power Jupiter’s Polar Aurorae?
Magnetic reconnection events less than 2 Jovian radii above the planet’s cloud tops could explain why Juno has yet to observe a source for Jupiter’s polar aurore.
Juno Detects Jupiter’s Highest-Energy Ions
Trapped ions discovered at midlatitudes can have energies exceeding 100 megaelectron volts per nucleon. Their detection adds to our understanding of the powerful radiation environment around Jupiter.
Fingerprints of Jupiter Formation
Meteorite isotopes, meteorite paleomagnetics, and planet formation models collectively show Jupiter formation via first slow then fast collection of material by core accretion in <5 million years.
Dawn Storms at Jupiter
Juno spacecraft observations provide the first global description of dawn storms in Jupiter’s aurorae, from their initiation to their end.