GED Science TestEarth and Space ScienceHard
A planetary scientist is analyzing data from a distant exoplanet. The data indicates that the planet has a very thin atmosphere, a heavily cratered surface, and a rotation period that is exceptionally slow, resulting in extreme temperature differences between its day and night sides. Based on these characteristics, which of the following Earth-like celestial bodies does this exoplanet most closely resemble?
- AEarth
- BMars
- CVenus
- DMoon
Show answer & explanationAnswer & explanation
Correct answer: D. Moon
The description of a very thin atmosphere, heavily cratered surface, and slow rotation leading to extreme temperature differences strongly aligns with the characteristics of Earth's Moon. Mars has a thin atmosphere and craters but a more moderate rotation. Venus has a very dense atmosphere, and Earth has a substantial atmosphere and rapid rotation.
Why the other options are wrong
- A. Earth has a thick atmosphere, rapid rotation, and less cratering due to geological activity.
- B. Mars has a thin atmosphere and craters, but its rotation is similar to Earth's, leading to less extreme temperature swings.
- C. Venus has an extremely dense atmosphere and a very slow rotation, but its surface is not heavily cratered like the description.
Lunar Characteristics
The Moon is characterized by a lack of substantial atmosphere, a heavily cratered surface, and a slow rotation, resulting in significant temperature variations.
- Surface is dominated by impact craters, maria (volcanic plains), and highlands.
- No significant atmosphere means no weather or erosion by wind/water.
- Synchronous rotation with Earth means one side always faces Earth.
Memory trick: Thin Air, Slow Spin, Craters Deep: Moon's Secrets Planets Keep.