The Solar System - Word Search - PUZZLE #13 CALLISTO - August 2025

PUZZLE #13 - CALLISTO 

IN-CONTEXT WORD DEFINITIONS

Frozen: Callisto’s surface is frozen, made mostly of water ice mixed with rock. Its surface temperature is extremely cold, averaging about -139°C (-218°F).

Valhalla Basin: The Valhalla Basin is Callisto’s largest impact structure — a huge multi-ring crater system over 3,800 km (2,360 miles) wide, formed by a massive collision in the distant past.

Asgard Basin: The Asgard Basin is another large, ancient multi-ring impact structure on Callisto. Smaller than Valhalla, it still spans over 1,600 km (1,000 miles) and shows the moon’s intense cratering history.

Radiation Belt: Unlike Europa or Ganymede, Callisto orbits outside Jupiter’s harsh radiation belts, making it one of the safest Galilean moons for potential human exploration or colonization.

Low Density: Callisto has low density (about 1.83 g/cm³), indicating it is composed of a roughly equal mix of rock and ice, with little or no dense metallic core like Ganymede or Earth.

Galileo: NASA’s Galileo spacecraft studied Callisto during its mission in the 1990s and early 2000s, providing detailed images of its surface features, composition, and magnetic environment.

Colonization: Because it is geologically stable and lies outside Jupiter’s intense radiation zone, Callisto is considered a prime candidate for future human colonization or long-term bases, such as for a waystation in deep-space missions.

Undifferentiated: Callisto is described as undifferentiated because it likely never fully separated into layers like core, mantle, and crust. Its interior may remain a mixed, primitive combination of ice and rock, making it a valuable object for studying the early solar system.

CALLISTO: CALLISTO is the second-largest of Jupiter’s moons and the third-largest moon in the solar system. It was discovered by Galileo Galilei in 1610 and is named after a nymph from Greek mythology.

Secret Word: refers to a slightly flattened, nearly spherical shape. Callisto is classified as an oblate spheroid, meaning it is mostly round but slightly flattened at the poles due to its slow rotation and the effects of gravity. This shape is typical for large celestial bodies that have enough mass for their gravity to pull them into a rounded form, but not perfectly spherical due to rotational or tidal forces.