Space Environment — Radiation Belts Radiation belts (zones of trapped energetic charged particles guided by magnetic fields) are found surrounding which planets?

Introduction / Context:
Planetary magnetospheres can trap high-energy particles from the solar wind and cosmic rays, forming radiation belts that affect spacecraft operations and planetary space weather. Recognizing which planets possess significant belts is basic space-science knowledge.

Given Data / Assumptions:

• Radiation belts require a sufficiently strong, structured planetary magnetic field.
• We consider the well-documented belts around Earth and the giant planets.
• We choose among options that include single or multiple planets.

Concept / Approach:

Earth hosts the Van Allen belts. Gas giants like Jupiter and Saturn have even more intense and extensive belts due to strong magnetic fields and rapid rotation. Mercury’s magnetic field is weak and its capacity to sustain robust radiation belts is limited compared to these planets. Therefore, the best answer among the options is the combined set: Earth, Jupiter, and Saturn.

Step-by-Step Solution:

Identify requirement: substantial magnetosphere.Recall known belts: Earth (Van Allen); Jupiter and Saturn have strong belts.Select the multi-planet option listing all with prominent belts.

Verification / Alternative check:

Spacecraft measurements (Explorer, Pioneer, Voyager, Cassini, Juno) directly observed trapped-particle populations around these planets, confirming strong belts.

Why Other Options Are Wrong:

Earth only / Jupiter & Saturn only: Incomplete.Mercury: Weak field; not known for strong Van Allen–type belts like the others.

Common Pitfalls:

Assuming all magnetized planets have belts of comparable intensity; Jupiter’s belts far exceed Earth’s in severity for spacecraft.

Final Answer:

Earth, Jupiter and Saturn