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 student wants a concise overview of the DART mission’s achievement for an article about protecting Earth from hazardous space objects.
So the best choice should summarize both (1) what DART did and (2) why that result matters for planetary defense.
Identify the most relevant notes
The notes emphasize these key points:
- 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.
- This was the first practical demonstration of a planetary-defense technique.
The best sentence should combine these points without adding new information.
Eliminate choices that miss key outcomes or add unsupported details
- Choice 1 mentions the collision and the relationship between Dimorphos and Didymos, but it leaves out the shortened orbital period and the planetary-defense significance.
- Choice 2 includes details not found in the notes (such as launching in 2021 and traveling for months).
- Choice 3 is too general (“missions like DART”) and doesn’t give a specific overview of what DART did and accomplished.
Select the choice that matches the notes and goal
The choice that accurately combines the action (intentional impact), the target (Dimorphos, a moonlet of Didymos), and the outcomes (shortened orbital period and a planetary-defense demonstration) is:
In 2022, NASA’s DART spacecraft intentionally hit Dimorphos, a moonlet of Didymos, shortening Dimorphos’s orbital period and demonstrating a planetary-defense technique.