GED Science TestEarth and Space ScienceMedium
A space agency is planning a mission to a newly discovered exoplanet. Data indicates the exoplanet has a thick atmosphere composed primarily of hydrogen and helium, a low density, and a strong magnetic field. Based on this information, which type of planet is it most likely to be?
- ATerrestrial planet
- BDwarf planet
- CGas giant
- DIce giant
Show answer & explanationAnswer & explanation
Correct answer: C. Gas giant
The characteristics described – thick hydrogen/helium atmosphere, low density, and strong magnetic field – are hallmarks of a gas giant planet, similar to Jupiter or Saturn in our solar system.
Why the other options are wrong
- A. Terrestrial planets are rocky, dense, and have thin atmospheres.
- B. Dwarf planets are smaller, often rocky or icy, and do not fit this description.
- D. Ice giants (like Uranus/Neptune) have more 'ices' (water, methane, ammonia) in their composition.
Gas Giant
A gas giant is a large planet composed mainly of hydrogen and helium, with a relatively small, dense core and a thick atmosphere.
- Low average density compared to terrestrial planets.
- Strong magnetic fields are common.
- Examples: Jupiter, Saturn.
Memory trick: Gassy giants hum with strong magnetic fields, light as a feather, but oh so big!