K. Magee

TL;DR: In this article, the authors summarize the geological evidence regarding an extant subsurface ocean, concentrating on Galileo imaging data and assess nine pertinent lines of geological evidence: impact morphologies, lenticulae, cryovolcanic features, pull-apart bands, chaos, ridges, surface frosts, topography, and global tectonics.

TL;DR: Io has been monitored during the nominal Galileo satellite tour from mid 1996 through late 1997 by the Solid State Imaging (SSI) experiment, which was able to observe many manifestations of active volcanism, including changes in the color and albedo of the surface, active airborne plumes, and glowing vents seen in eclipse as discussed by the authors.

TL;DR: Banfieldet et al. as discussed by the authors measured a strong northeast flow approaching the hot spot, indicating either massive horizontal convergence or the presence of a large anticyclonic vortex southeast of the hot spots.

TL;DR: During late 1999/early 2000, the solid state imaging experiment on the Galileo spacecraft returned more than 100 high-resolution images of volcanically active Io, observing an active lava lake, an active curtain of lava, active lava flows, calderas, mountains, plateaus, and plains.

TL;DR: In this paper, the authors calculated the transient crater dimensions and excavation depths of all primary impact features >4 km in diameter seen on Europa (through orbit E19) and found that the transition from simple to complex crater morphology occurs at a diameter of about 5 km.