The Earth is not the only world. There are billions of other potential

Question

The Earth is not the only world. There are billions of other potential homes for life. The planet Mars, the closest such home, is a world of towering mountains, vast deserts, polar ice fields, dry river channels, and spectacular deep canyons. Orbiting the Sun at a distance about 50 percent greater than that of the Earth, Mars is a cold world. During the day, the temperature frequently exceeds 50 degree Fahrenheit. At night, however, the thin Martian atmosphere does a poor job of retaining heat, and temperature drops to negative 130 degree Fahrenheit.

There is no liquid water on the surface of Mars today, but our satellite probes show large networks of dried up ocean basins. The water, however, is there – its surface reserves frozen as ice and covered with dust. On the Earth, whenever we find liquid water, we find life. Our orbital images show that there was liquid water on the surface of Mars for about a billion years of the planet’s early history,  a span at least ten times as long as  it took for life to appear in the Earth’s fossil records after there was liquid water there. Thus, if the conjecture is correct that life is a natural development from chemistry whenever one has liquid water and a sufficient period of time, then life should have appeared on Mars.

Life may have lost its foothold on the planet’s surface, with the loss of the juvenile Mars’s early thick carbon dioxide atmosphere and its associated greenhouse warming capability. But our space probes show that liquid water has gushed out from Mars’s surface within the past few million years, and probably within the past decade. In either case, it means that refuges for retreating Martian life may still exist. If we go there and drill, we could find them and determine whether life as we know it on the Earth is the pattern for all life everywhere or whether we are just one example of a much vaster and more varied tapestry.    1 
 1. The passage makes the comparison indicated in the highlighted text to imply that

A. Mars is older than the Earth
B. Mars may have life on it today
C. Mars may have life on it in future
D. Mars may have had life on it in the past
E. Water is not the only requirement for life

2 
 2. The information in the passage suggests that which of the following statements is true?

A. In the young age of Mars, the Martian atmosphere was thinner than the Earth’s atmosphere.
B. Mars’s frozen water is melting at an increasing rate over the last few million years.
C. Carbon dioxide in a planet’s atmosphere is detrimental to life on the planet.
D. Mars is about a billion years old. 
E. Life may not be developed in frozen water.

3 
 3. Which of the following is the author NOT likely to agree with?

A. We do not yet know whether life as we know it on the Earth is the only form of life.
B. Mars’s surface consists of varied geographical features. 
C. A billion years is sufficient time for life to appear on any planet.
D. Life may be existing on planets other than the Earth.
E. Mars’s temperature undergoes wide swings every day.

4 
 4. The passage indicates which of the following as the cause for the disappearance of life from the surface of Mars?

A. Loss of Mars’s thick carbon dioxide atmosphere.
B. Extreme shifts in temperature during day and night.
C. Cold temperature on Mars.
D. Mars’s orbit is farther from the Sun than that of the Earth is.
E. Mars has existed for ten times longer than life on Earth has.

Username1512 · Answer

Shouldn’t 4 be C? The ultimate reason for disappearance of life is the cold temp. The loss of carbon dioxide atmosphere is intermediate reason at most.

bhanu29 · Answer

The Earth is not the only world. There are billions of other potential homes for life. The planet Mars, the closest such home, is a world of towering mountains, vast deserts, polar ice fields, dry river channels, and spectacular deep canyons. Orbiting the Sun at a distance about 50 percent greater than that of the Earth, Mars is a cold world. During the day, the temperature frequently exceeds 50 degree Fahrenheit. At night, however, the thin Martian atmosphere does a poor job of retaining heat, and temperature drops to negative 130 degree Fahrenheit.

There is no liquid water on the surface of Mars today, but our satellite probes show large networks of dried up ocean basins. The water, however, is there – its surface reserves frozen as ice and covered with dust. On the Earth, whenever we find liquid water, we find life. Our orbital images show that there was liquid water on the surface of Mars for about a billion years of the planet’s early history,  a span at least ten times as long as  it took for life to appear in the Earth’s fossil records after there was liquid water there. Thus, if the conjecture is correct that life is a natural development from chemistry whenever one has liquid water and a sufficient period of time, then life should have appeared on Mars.

Life may have lost its foothold on the planet’s surface, with the loss of the juvenile Mars’s early thick carbon dioxide atmosphere and its associated greenhouse warming capability. But our space probes show that liquid water has gushed out from Mars’s surface within the past few million years, and probably within the past decade. In either case, it means that refuges for retreating Martian life may still exist. If we go there and drill, we could find them and determine whether life as we know it on the Earth is the pattern for all life everywhere or whether we are just one example of a much vaster and more varied tapestry.

1. The passage makes the comparison indicated in the highlighted text to imply that

A. Mars is older than the Earth
B. Mars may have life on it today
C. Mars may have life on it in future
D. Mars may have had life on it in the past
E. Water is not the only requirement for life

https://www.youtube.com/watch?v=NgYhueo4Mjk

2. The information in the passage suggests that which of the following statements is true?

A. In the young age of Mars, the Martian atmosphere was thinner than the Earth’s atmosphere.
B. Mars’s frozen water is melting at an increasing rate over the last few million years.
C. Carbon dioxide in a planet’s atmosphere is detrimental to life on the planet.
D. Mars is about a billion years old. 
E. Life may not be developed in frozen water.

https://www.youtube.com/watch?v=OeO9EJzRIdU

3. Which of the following is the author NOT likely to agree with?

A. We do not yet know whether life as we know it on the Earth is the only form of life.
B. Mars’s surface consists of varied geographical features. 
C. A billion years is sufficient time for life to appear on any planet.
D. Life may be existing on planets other than the Earth.
E. Mars’s temperature undergoes wide swings every day.

https://www.youtube.com/watch?v=V1UHKrM174I

4. The passage indicates which of the following as the cause for the disappearance of life from the surface of Mars?

A. Loss of Mars’s thick carbon dioxide atmosphere.
B. Extreme shifts in temperature during day and night.
C. Cold temperature on Mars.
D. Mars’s orbit is farther from the Sun than that of the Earth is.
E. Mars has existed for ten times longer than life on Earth has.

https://www.youtube.com/watch?v=BRuxX7xlrLk

egmat · Answer

Great question, but there's an  important  nuance you're missing here about how GMAT RC works.

The question asks what the passage INDICATES as the cause. This means we need to find what the passage explicitly states, not what we might logically infer on our own.

The passage says: life may have lost its foothold "with the loss of the juvenile Mars's early thick carbon dioxide atmosphere and its associated greenhouse warming capability."

This sentence directly names the loss of the CO 2  atmosphere as the cause. That's answer  A , word for word.

Now, your reasoning isn't entirely illogical — yes, losing the CO 2  atmosphere led to cooling, and cooling led to water freezing, which hurt life. But here's the problem:  you're building a causal chain that goes beyond what the passage states . The passage never says "cold temperature caused life to disappear." It says the loss of the atmosphere did.

Think of it this way: the question is like asking "What does the doctor's report say caused the illness?" If the report says "a bacterial infection," that's the answer — even if YOU think the ultimate cause was the patient's weak immune system. We go by what the source states.

Also,  note that  cold temperature (choice C) describes Mars's CURRENT condition. The passage mentions the daily temperature swings in the first paragraph as a general fact about Mars today,  not as a reason life disappeared .

Key principle:  On GMAT RC detail questions, stick to what the passage explicitly states. Don't substitute your own causal reasoning for the author's stated explanation.

Answer: A

The Earth is not the only world. There are billions of other potential

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The Earth is not the only world. There are billions of other potential

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615 to 715 in 15 Days (Ria's Strategies)

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Perfect 805 Score Debrief by Julia

My Rewards