Although it's clear that Mars once had liquid water on its surface, astronomers have debated whether the evidence of ancient...
GMAT Information and Ideas : (Ideas) Questions
Although it's clear that Mars once had liquid water on its surface, astronomers have debated whether the evidence of ancient water reflects a prolonged phase of warm, wet conditions - the so-called wet and warm scenario - or a brief period of melting in an otherwise consistently frozen environment. Researchers Benjamin T. Cardenas and Michael P. Lamb recently added to this debate by using data from NASA and the Mars Orbiter Laser Altimeter to map the topography of what is now a large basin in Mars's northern hemisphere. Cardenas and Lamb concluded that the wet and warm scenario is likely correct.
Which finding about the basin, if true, would most directly support Cardenas and Lamb's conclusion?
Step 1: Decode and Map the Passage
Part A: Create Passage Analysis Table
| Text from Passage | Analysis |
|---|---|
| "Although it's clear that Mars once had liquid water on its surface, astronomers have debated whether the evidence of ancient water reflects a prolonged phase of warm, wet conditions—the so-called wet and warm scenario—or a brief period of melting in an otherwise consistently frozen environment." | What it says: Mars had water; debate = long warm/wet period vs short melting period What it does: Introduces the central scientific debate about Mars's water history What it is: Background context establishing two competing theories |
| "Researchers Benjamin T. Cardenas and Michael P. Lamb recently added to this debate by using data from NASA and the Mars Orbiter Laser Altimeter to map the topography of what is now a large basin in Mars's northern hemisphere." | What it says: C&L = new researchers; used NASA data to map basin topography What it does: Introduces new research that contributes to the existing debate What it is: New evidence/study description |
| "Cardenas and Lamb concluded that the wet and warm scenario is likely correct." | What it says: C&L support wet/warm scenario What it does: Presents the researchers' conclusion favoring one side of the debate What it is: Research conclusion/claim |
Part B: Provide Passage Architecture & Core Elements
Main Point: New research by Cardenas and Lamb supports the theory that Mars experienced prolonged warm, wet conditions rather than just brief melting periods.
Argument Flow: The passage establishes an ongoing scientific debate about whether Mars's ancient water evidence indicates long-term warm conditions or short-term melting. It then introduces new research that used topographical mapping to study a Martian basin, leading to a conclusion that supports the prolonged warm, wet scenario.
Step 2: Interpret the Question Precisely
What's being asked? Which finding about the basin would most directly support Cardenas and Lamb's conclusion
What type of answer do we need? Evidence that would strengthen their conclusion that the "wet and warm scenario" (prolonged warm, wet conditions) is correct
Any limiting keywords? "most directly support" - we need the strongest, most relevant evidence for their specific conclusion
Step 3: Prethink the Answer
- The researchers concluded that Mars had prolonged warm, wet conditions rather than brief melting periods
- To support this conclusion, we'd need evidence showing:
- Long-term water activity (not short-term)
- Gradual or sustained processes (not sudden events)
- Features that require extended time to develop
- The right answer should describe basin characteristics that indicate sustained, long-term water presence rather than brief flooding or melting events
- This tells us the basin wasn't formed by an impact event
- While this might eliminate one formation mechanism, it doesn't directly support prolonged water activity over brief melting
- Doesn't distinguish between the two competing water scenarios
- Features suggesting an ancient ocean with gradual sea-level changes over extended time
- "Gradual" and "extended time" directly support prolonged warm, wet conditions
- This type of sustained oceanic activity contradicts the brief melting scenario
- Describes formation from "massive but short-lived influx of liquid water"
- "Short-lived" directly contradicts Cardenas and Lamb's conclusion
- This would actually support the brief melting scenario they rejected
- Channels could be formed by either water or lava
- Too ambiguous to strongly support either water scenario
- Doesn't provide clear evidence distinguishing between prolonged vs. brief water activity