Until the Apollo astronauts brought samples of lunar material to Earth during 1969-72, scientists believed that the Moon's surface was...
GMAT Reading Comprehension : (RC) Questions
Until the Apollo astronauts brought samples of lunar material to Earth during 1969-72, scientists believed that the Moon's surface was largely undisturbed, given its dry, airless environment. Examination of the samples has shown otherwise. Micrometeorites, many smaller than a pencil point, constantly rain onto the Moon at up to 100,000 kilometers per hour, chipping materials or forming microscopic craters. Some melt the soil and vaporize and recondense as glassy coats on other specks of dust. Impacts weld debris into lumps of heterogeneous matter called "agglutinates." Complicated interactions with solar particle streams convert iron into myriads of microscopic iron grains. The regolith-pebbles, sand, and dust- from these erosion processes blankets the Moon. Much of the top layer consists of a complex abrasive dust of microscopic glass shards that can grind machinery and sealing devices and damage human lungs.
The Apollo specimens held by the United States are doled out in ultra-small samples to scientists who demonstrate that nothing else will suffice for high-value experiments. Renewed interest in lunar exploration in the late 1980s meant that materials designed to simulate lunar regolith-simulants -were needed for research to develop schemes for lunar building and procedures for extracting elements such as oxygen found abundantly in regolith. That led to the development of JSC-1 in 1993, made of volcanic cinder cone from a quarry in Arizona in the U.S. The more than 22 metric tons made was in high demand. Efforts are now afoot to manufacture 16 metric tons of JSC-1A, with 1 ton of fine grains, 14 tons of moderately fine, and 1 ton of coarse.
Currently, three new simulants are being developed. Two will represent the Moon's dry seas region and polar highlands region. A third will represent the glassy, jagged edges of lunar dust that test the best of hardware and humans. But since matching every lunar location would require large numbers of small, unique, expensive batches, the intention is to develop a few "root simulants," blends of which will yield regionally specific simulants. For example, ilmenite, a crystalline iron-titanium oxide, is a crucial ingredient for the new dry seas region simulant. Raw materials for the three new stimulants will come from sites in the U.S. and even some international sites
The information in the passage most strongly supports which of the following claims about the samples of lunar material brought back from the Moon by the Apollo astronauts?
1. Passage Analysis:
Progressive Passage Analysis
| Text from Passage | Analysis |
|---|---|
| Until the Apollo astronauts brought samples of lunar material to Earth during 1969-72, scientists believed that the Moon's surface was largely undisturbed, given its dry, airless environment. | What it says: Before Apollo missions, scientists thought the Moon's surface was basically unchanged because it's dry and has no air. What it does: Sets up the initial misconception that the rest of the passage will correct Source/Type: Historical fact about scientific beliefs Connection to Previous Sentences: This is the opening - establishes the "before" state Visualization: Before 1969: Scientists' belief = Moon surface = undisturbed/unchanged Reading Strategy Insight: Watch for contrast - this "believed" suggests the belief was wrong |
| Examination of the samples has shown otherwise. | What it says: The Apollo samples proved scientists were wrong What it does: Directly contradicts the previous belief and signals what's coming Source/Type: Factual conclusion from scientific evidence Connection to Previous Sentences: This is the pivotal contrast - "otherwise" means the opposite of "largely undisturbed" Visualization: Before 1969: Scientists thought Moon = undisturbed → After examining samples: Moon = actually very disturbed Reading Strategy Insight: This is your roadmap! The rest will explain HOW the Moon is disturbed |
2. Passage Summary:
Author's Purpose:
To explain how scientists discovered the Moon's surface is much more active than originally thought, and to describe how they developed artificial moon materials to solve the problem of limited real samples for research.
Summary of Passage Structure:
In this passage, the author walks us through a complete story of scientific discovery and practical problem-solving:
- First, the author sets up the old scientific belief that the Moon's surface was basically unchanged, then immediately reveals this belief was wrong based on Apollo sample evidence.
- Next, the author explains in detail how the Moon's surface is actually very active, with tiny meteorites and solar particles constantly changing it and creating a layer of material called regolith that can be dangerous to humans and equipment.
- Then, the author shifts to explain the practical problem this creates - real Moon samples are very limited, but scientists need lots of material to test things for future Moon missions.
- Finally, the author describes how scientists solved this problem by creating fake Moon materials called simulants, starting with basic versions in the 1990s and now developing sophisticated region-specific types that can be mixed together efficiently.
Main Point:
Scientists have learned that the Moon's surface is much more complicated and active than they first thought, and because real Moon samples are too precious to use freely, they've gotten very good at making artificial substitutes that let them prepare for future Moon exploration.
Question Analysis:
This question asks us to identify which claim about the Apollo lunar samples is most strongly supported by the passage. We need to look for information specifically about the Apollo samples themselves - not about lunar regolith in general or simulants, but about the actual materials brought back by the astronauts.
Connecting to Our Passage Analysis:
From our passage analysis, we identified several key points about the Apollo samples:
- The samples revealed that scientists' original beliefs about the Moon were wrong - the surface was actually very disturbed, not undisturbed
- The samples are held by the United States and are extremely precious/limited
- Most importantly, the passage states: "The Apollo specimens held by the United States are doled out in ultra-small samples to scientists who demonstrate that nothing else will suffice for high-value experiments"
- This scarcity problem led to the need for simulants - artificial substitutes for research that doesn't absolutely require real lunar material
Prethinking:
The passage structure moves from describing what the Apollo samples revealed about the Moon, to explaining how scarce these samples are, to describing the simulant solution. The key insight is that the Apollo samples are so valuable that they're only given to scientists who can prove they absolutely need real lunar material and that nothing else (like simulants) would work for their specific experiments. This suggests that scientists who could use simulants instead are not considered eligible for the precious Apollo samples.
Why It's Right:
- The passage directly states that Apollo samples are only given to scientists who "demonstrate that nothing else will suffice for high-value experiments"
- This clearly implies that if JSC-1A (a simulant) would suffice for a scientist's experiment, they would not be entitled to receive real Apollo samples
- The entire simulant development story supports this - simulants exist precisely so that precious real samples can be reserved only for experiments that absolutely require them
Key Evidence: "The Apollo specimens held by the United States are doled out in ultra-small samples to scientists who demonstrate that nothing else will suffice for high-value experiments."
Why It's Wrong:
- The passage doesn't restrict Apollo sample access to only simulant developers
- The passage indicates samples go to any scientists with "high-value experiments" that require real lunar material, regardless of their specific research focus
- Simulant developers might actually be less likely to need real samples since they're creating substitutes
Common Student Mistakes:
- Did the passage mention simulant developers getting special access to samples? → No, the passage explains simulants were created because of sample scarcity, not because certain scientists get preferential access
- Are simulant developers the only ones doing lunar research? → No, the passage suggests many different types of scientists need lunar materials for various experiments
Why It's Wrong:
- The passage doesn't provide information about what types of regolith the Apollo samples contained
- The fact that scientists are now developing region-specific simulants suggests the original samples may not have represented all major types
- The passage focuses on what the samples revealed about lunar processes, not on their comprehensiveness
Common Student Mistakes:
- Since scientists learned so much from the samples, did they contain everything? → Learning about lunar processes doesn't mean the samples contained all regional variations
- Does the development of region-specific simulants prove the samples were comprehensive? → Actually, it suggests the opposite - if samples were comprehensive, why develop region-specific alternatives?
Why It's Wrong:
- The passage states that volcanic cinder cone material comes from Arizona quarries on Earth, not from lunar volcanoes
- JSC-1 simulant ingredients are terrestrial materials chosen to mimic lunar properties
- The passage makes no mention of volcanic activity on the Moon
Common Student Mistakes:
- Since JSC-1 uses volcanic cinder cone, did this come from the Moon? → No, the passage clearly states it comes "from a quarry in Arizona in the U.S."
- Are the Apollo samples and simulant ingredients the same thing? → No, simulants are artificial substitutes made from Earth materials to mimic lunar properties
Why It's Wrong:
- The passage mentions ilmenite as an ingredient for simulants, not as content found in Apollo samples
- There's no information provided about how many samples contained ilmenite or any specific minerals
- The passage doesn't give detailed compositional analysis of the individual Apollo samples
Common Student Mistakes:
- Since ilmenite is mentioned in connection with lunar research, was it found in the samples? → The passage only mentions ilmenite as a simulant ingredient, not as a sample component
- Does the passage provide detailed information about what was in each sample? → No, it focuses on what the samples revealed about lunar processes, not their individual compositions