In 2019, 20 previously unknown moons were confirmed to be orbiting Saturn. Three of the moons have prograde orbits (orbiting...
GMAT Information and Ideas : (Ideas) Questions
In 2019, 20 previously unknown moons were confirmed to be orbiting Saturn. Three of the moons have prograde orbits (orbiting in the direction the planet spins), and the other 17 have retrograde orbits (orbiting in the opposite direction of the planet's spin). All but one of the 20 moons are thought to be remnants of bodies that orbited Saturn until they broke apart in collisions. Although the one exceptional moon orbits in the same direction as the planet's spin, its orbit is highly eccentric compared to the rest, which may suggest that it has a different origin than the other 19 moons.
Based on the text, which choice best describes the moon with the eccentric orbit?
It doesn't have a retrograde orbit, but it likely has the same origin as the moons with retrograde orbits.
Its orbit is so tilted with respect to the other moons' orbits that it's neither prograde nor retrograde.
It has a prograde orbit that is likely the result of having collided with another body orbiting Saturn.
It has a prograde orbit and may not be a remnant of an earlier body that orbited Saturn.
Step 1: Decode and Map the Passage
Create Passage Analysis Table
| Text from Passage | Analysis |
|---|---|
| "In 2019, 20 previously unknown moons were confirmed to be orbiting Saturn." |
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| "Three of the moons have prograde orbits (orbiting in the direction the planet spins), and the other 17 have retrograde orbits (orbiting in the opposite direction of the planet's spin)." |
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| "All but one of the 20 moons are thought to be remnants of bodies that orbited Saturn until they broke apart in collisions." |
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| "Although the one exceptional moon orbits in the same direction as the planet's spin, its orbit is highly eccentric compared to the rest, which may suggest that it has a different origin than the other 19 moons." |
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Provide Passage Architecture & Core Elements
Main Point: Among 20 newly discovered Saturn moons, one stands out with both a prograde orbit and unusual characteristics that suggest it may have formed differently than the others.
Argument Flow: The passage starts with the discovery announcement, then categorizes the moons by orbit direction, explains that most are collision remnants, and finally highlights one exceptional moon whose unique orbital characteristics suggest a different formation history.
Step 2: Interpret the Question Precisely
What's being asked? We need to describe the moon with the eccentric orbit based on the passage information.
What type of answer do we need? A description that accurately captures the key characteristics and implications mentioned in the passage.
Any limiting keywords? "Based on the text" means we must stick to what's explicitly stated or directly implied in the passage.
Step 3: Prethink the Answer
- From our analysis, the eccentric moon has three key features: it has a prograde orbit (same direction as Saturn's spin), it has an eccentric orbit compared to other moons, and it may have a different origin than the other 19 moons
- The passage suggests that while most moons are collision remnants, this one might not be
It doesn't have a retrograde orbit, but it likely has the same origin as the moons with retrograde orbits.
✗ Incorrect
- Claims the moon "likely has the same origin as the moons with retrograde orbits." This directly contradicts the passage, which suggests it "may have a different origin than the other 19 moons."
Its orbit is so tilted with respect to the other moons' orbits that it's neither prograde nor retrograde.
✗ Incorrect
- Claims the orbit is "neither prograde nor retrograde." The passage clearly states this moon "orbits in the same direction as the planet's spin," which is the definition of prograde.
It has a prograde orbit that is likely the result of having collided with another body orbiting Saturn.
✗ Incorrect
- Claims it's "likely the result of having collided with another body." This contradicts the passage's suggestion that this moon may have a different origin from the collision remnants.
It has a prograde orbit and may not be a remnant of an earlier body that orbited Saturn.
✓ Correct
- Accurately states it has a prograde orbit and correctly captures that it "may not be a remnant of an earlier body that orbited Saturn." This aligns perfectly with the passage.