PASADENA, Calif. NASA has released some of the closest looks yet at two of Jupiters 16 moons, including details of icy Europas tortured crust and lava flows on volcanic Io that would be right at home on the island of Hawaii.

NASAs Galileo spacecraft snapped the pictures during several recent encounters with the jovian moons, including a February 22 flyby of Io.

That rendezvous, the results of which have not been previously released to the public, gives one of the highest-resolution peeks ever at Ios lava flows. The black-and-white image, seen below, shows features as small as 23 feet (7 meters) across. (The black stripes mark places where data was lost during transmission to Earth.)

The highest-ever resolution look at Jupiter's moon Io, showing Hawaii-like lava flows. The smallest objects seen are 23 feet (7 meters) across. The bottom false-color image shows lava flows in Io's caldera Chaac.

The color image above shows lava flows on the floor of the caldera Chaac, a depression formed during the course of a volcanic eruption. Chaac -- named for the Mayan god of rain -- is approximately 63 miles (100 kilometers) long and 19 miles (30 kilometers) across. The flows in the picture resemble those found within Hawaiis Kilauea volcano.

In the image below, Galileo focused on the Jupiter-facing side of Europa, revealing its bright, icy surface in sharp contrast with darker, non-ice materials. Scientists believe the dark material could be either salty minerals, kicked up from the liquid ocean that likely lurks beneath the ice, or sulfuric acid.

The highest-resolution image ever of icy Europa's Jupiter-facing side, acquired Feb. 22, 2000 by Galileo.

In the final image, below, Galileo reveals terrain near Ios southern pole, including more volcanic calderas (seen as black spots), sulfur-rich lava flows (seen in yellow) and scattered fields of blinding white sulfur-dioxide frost.

Volcanic calderas, lava flows and cliffs near Io's south pole.

The image also shows at center left a mountain called Telegonus Mensae, which appears to be collapsing outward under the influence of gravity.

Galileo is on the home stretch of a scientific mission that began in 1995 with its arrival at Jupiter after a six-year journey. The Galileo Millennium Mission -- its second mission extension -- will next swing the orbiting spacecraft by the moon Ganymede on May 30, and again on December 28.

Plans also call for Galileo and the Saturn-bound Cassini probe to make several months worth of joint observations of Jupiter as the latter spacecraft flies by for a gravity assist in December.