Question 169·Medium·Rhetorical Synthesis
While researching a topic, a student has gathered the following notes:
- The Double Asteroid Redirection Test (DART) is a NASA mission.
- In 2022, the DART spacecraft intentionally collided with the asteroid Dimorphos.
- Dimorphos is a moonlet orbiting the larger asteroid Didymos.
- The impact shortened Dimorphos’s orbital period around Didymos.
- The mission provided the first practical demonstration of a planetary-defense technique.
The student is writing an article about methods of protecting Earth from hazardous space objects and wants to give readers a concise overview of the DART mission’s achievement.
Which choice most effectively uses relevant information from the notes to accomplish this goal?
For note-synthesis questions, start by underlining the task words in the prompt (for example, concise overview, achievement, methods of protecting Earth). Then scan the notes to identify which bullets are central to that task (usually the result or purpose, not just background facts). Evaluate each answer by asking: Does it (1) use several of the most important notes, especially the outcome or significance; (2) stay focused on the stated goal; and (3) avoid adding details not in the notes or leaving out key points? Eliminate choices that are too vague, too narrow, or that introduce unsupported information, and pick the one that best and most efficiently summarizes the relevant notes.
Hints
Focus on the writing goal
Re-read the question stem. The student wants a concise overview of the DART mission’s achievement for an article about methods of protecting Earth. Which options actually explain what DART accomplished for planetary defense, rather than just stating mission facts?
Identify the key achievement in the notes
Look back at the bullet points. Which ones describe what changed because of DART and what that demonstrated, instead of just giving background details like names or relationships?
Watch for missing or extra information
Check whether an option (1) leaves out important results from the notes, such as what the impact did, or (2) adds details that are not mentioned in the notes at all. The best answer should stick closely to the provided information and the stated purpose.
Step-by-step Explanation
Clarify the student’s goal
The question says the student is writing about methods of protecting Earth from hazardous space objects and wants a concise overview of the DART mission’s achievement.
So the right answer must:
- Focus on what DART actually accomplished (its result or achievement), not just basic facts.
- Connect that accomplishment to planetary defense (protecting Earth).
Pull out the most important notes
From the notes, identify what counts as the mission’s main achievement, especially for planetary defense:
- DART is a NASA mission.
- In 2022, the DART spacecraft intentionally collided with Dimorphos.
- Dimorphos is a moonlet orbiting the larger asteroid Didymos.
- The impact shortened Dimorphos’s orbital period around Didymos.
- The mission provided the first practical demonstration of a planetary-defense technique.
A strong choice should use several of these points, especially the change in orbit and the first demonstration of a defense technique.
Eliminate options that are incomplete, off-focus, or unsupported
Check each choice against the notes and the goal:
- Choice A mentions the collision and orbit relationship but does not mention the shortened orbital period or planetary defense, so it does not explain the mission’s achievement.
- Choice B adds details like the launch year (2021) and traveling millions of miles, which are not in the notes and do not highlight the achievement or planetary-defense purpose.
- Choice C is vague and general (missions like DART) instead of giving a concise, specific overview of DART itself; it does not clearly summarize what DART did and how.
Only one choice correctly combines what DART did, its effect on Dimorphos, and its role as a first real-world planetary-defense test, all of which are in the notes.
Choose the sentence that fully matches the notes and the goal
The only option that accurately and concisely uses the key notes (intentional crash in 2022, Dimorphos as a moonlet of Didymos, shortened orbital period, and first test of a planetary-defense strategy) is:
NASA’s 2022 DART mission intentionally crashed a spacecraft into Dimorphos, a moonlet of the larger asteroid Didymos, shortening Dimorphos’s orbital period and providing the first real-world test of a planetary-defense strategy.