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14 Aug 2025, 07:47
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Most known exoplanets lie too far from Earth to be observed directly and must instead be identified using indirect detection methods, such as measuring starlight distortions or subtle gravitational wobbles. However, these methods can generate reliable signal data only if the planet’s host star emits light in stable and consistent patterns over time. Therefore, few exoplanets are likely to produce detectable signals that can be consistently detected unless they are close enough to Earth to be observed directly.
Which of the following is an assumption required by the argument?
A. Indirect detection methods are less reliable than direct observation when gathering data about planetary atmospheres.
B. There are no alternative methods of detecting reliable signal data from exoplanets other than through shifts in starlight distortions or gravitational wobbles
C. Reliable interpretation of signal-related data depends more on the characteristics of the host star than on the exoplanet itself.
D. Exoplanets orbiting stars with consistent emission patterns are less common than those orbiting stars with inconsistent emissions.
E. Some exoplanets orbit stars with stable emissions but still fail to produce reliably detectable signals.
Which of the following is an assumption required by the argument?
A. Indirect detection methods are less reliable than direct observation when gathering data about planetary atmospheres.
B. There are no alternative methods of detecting reliable signal data from exoplanets other than through shifts in starlight distortions or gravitational wobbles
C. Reliable interpretation of signal-related data depends more on the characteristics of the host star than on the exoplanet itself.
D. Exoplanets orbiting stars with consistent emission patterns are less common than those orbiting stars with inconsistent emissions.
E. Some exoplanets orbit stars with stable emissions but still fail to produce reliably detectable signals.
14 Aug 2025, 07:47
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Official Solution:
Most known exoplanets lie too far from Earth to be observed directly and must instead be identified using indirect detection methods, such as measuring starlight distortions or subtle gravitational wobbles. However, these methods can generate reliable signal data only if the planet’s host star emits light in stable and consistent patterns over time. Therefore, few exoplanets are likely to produce detectable signals that can be consistently detected unless they are close enough to Earth to be observed directly.
Which of the following is an assumption required by the argument?
A. Indirect detection methods are less reliable than direct observation when gathering data about planetary atmospheres.
B. There are no alternative methods of detecting reliable signal data from exoplanets other than through shifts in starlight distortions or gravitational wobbles
C. Reliable interpretation of signal-related data depends more on the characteristics of the host star than on the exoplanet itself.
D. Exoplanets orbiting stars with consistent emission patterns are less common than those orbiting stars with inconsistent emissions.
E. Some exoplanets orbit stars with stable emissions but still fail to produce reliably detectable signals.
Let’s break this argument down statistically for better clarity.
Let’s say out of 100 total exoplanets, 10 are close enough to Earth to be observed directly. The remaining 90 are too far and require indirect methods like those mentioned above.
So now we know that even for indirect methods to work, the host star must have stable emissions.
Whoa, that’s a leap! It’s saying unless an exoplanet is one of those 10 close ones, only a few of the remaining 90 will reliably produce communication signals.
Let’s say out of the 90 faraway exoplanets, only 20 orbit stars with stable emissions and therefore can be reliably detected. The remaining 70 orbit unstable stars, making detection inconsistent.
So to recap:
• 10 exoplanets (near) -> observable directly
• 90 exoplanets (far) -> need indirect methods - Out of these 90: 20 -> stable stars -> consistent signals & 70 -> unstable stars -> inconsistent signals
This whole conclusion only works if that distribution holds true and we’re supposed to find which assumption makes the argument logically follow.
Let's go through the options now -
A. Indirect detection methods are less reliable than direct observation when gathering data about planetary atmospheres.
- Do we know anything about a comparison between the results of direct and indirect methods? I don't think so. What we can reliably say is that for planets which are far away, we will need to use indirect methods. So this option is incorrect.
B. There are no alternative methods of detecting reliable signal data from exoplanets other than through shifts in starlight distortions or subtle gravitational wobbles
- Good trap. First trap is that it's talking about all exoplanets and not only the ones that are far away from Earth, whereas the near ones use direct methods for measurement.
Ideally you should have already eliminated this choice by now, if not,
Second, we definitely need to use indirect methods to detect exoplanets that are far from Earth, and a couple of techniques used are starlight distortions and gravitational wobbles.
But do we know there's no other indirect method apart from these two that can be used for this measurement?
The argument only discusses a few examples using the phrase "such as", so it would be a strong hypothesis to rule out any others as it's not explicitly stated in the argument and hence, this is not an implied assumption. And if there does exist other indirect methods to detect reliable signal data, does the conclusion break? Don't think so, as the conclusion was made for all indirect methods not the only ones mentioned in the argument.
C. Reliable interpretation of signal-related data depends more on the characteristics of the host star than on the exoplanet itself.
- This might be true, but it’s not implied in any way by the given argument.
It could well be the case that the characteristics of the host star are one attribute required for communication, but other attributes of the exoplanet like its structure and atmosphere could be equally important for reliable communication.
D. Exoplanets orbiting stars with consistent emission patterns are less common than those orbiting stars with inconsistent emissions.
- Right on point! As we noted from our earlier statistics, exoplanets with inconsistent emissions i.e., 70 out of 100 are far greater than the other ones. So this is clearly an assumption of the argument.
If we negate this, say the ones with consistent emissions are more common, then exoplanets with consistent host stars would likely be in the majority, and the conclusion that "few exoplanets are likely to produce communication signals that can be consistently detected" would completely fall apart.
E. Some exoplanets orbit stars with stable emissions but still fail to produce reliably detectable signals.
- Sure, this might be true, but the argument doesn’t need it. Even if 5 out of the 20 stable ones failed to produce signals, there would still be few left, and the conclusion would still stand. This isn’t something the argument depends on but it’s just extra information.
Answer: D
Most known exoplanets lie too far from Earth to be observed directly and must instead be identified using indirect detection methods, such as measuring starlight distortions or subtle gravitational wobbles. However, these methods can generate reliable signal data only if the planet’s host star emits light in stable and consistent patterns over time. Therefore, few exoplanets are likely to produce detectable signals that can be consistently detected unless they are close enough to Earth to be observed directly.
Which of the following is an assumption required by the argument?
A. Indirect detection methods are less reliable than direct observation when gathering data about planetary atmospheres.
B. There are no alternative methods of detecting reliable signal data from exoplanets other than through shifts in starlight distortions or gravitational wobbles
C. Reliable interpretation of signal-related data depends more on the characteristics of the host star than on the exoplanet itself.
D. Exoplanets orbiting stars with consistent emission patterns are less common than those orbiting stars with inconsistent emissions.
E. Some exoplanets orbit stars with stable emissions but still fail to produce reliably detectable signals.
Let’s break this argument down statistically for better clarity.
Quote:
Let’s say out of 100 total exoplanets, 10 are close enough to Earth to be observed directly. The remaining 90 are too far and require indirect methods like those mentioned above.
Quote:
So now we know that even for indirect methods to work, the host star must have stable emissions.
Quote:
Whoa, that’s a leap! It’s saying unless an exoplanet is one of those 10 close ones, only a few of the remaining 90 will reliably produce communication signals.
Let’s say out of the 90 faraway exoplanets, only 20 orbit stars with stable emissions and therefore can be reliably detected. The remaining 70 orbit unstable stars, making detection inconsistent.
So to recap:
• 10 exoplanets (near) -> observable directly
• 90 exoplanets (far) -> need indirect methods - Out of these 90: 20 -> stable stars -> consistent signals & 70 -> unstable stars -> inconsistent signals
This whole conclusion only works if that distribution holds true and we’re supposed to find which assumption makes the argument logically follow.
Let's go through the options now -
A. Indirect detection methods are less reliable than direct observation when gathering data about planetary atmospheres.
- Do we know anything about a comparison between the results of direct and indirect methods? I don't think so. What we can reliably say is that for planets which are far away, we will need to use indirect methods. So this option is incorrect.
B. There are no alternative methods of detecting reliable signal data from exoplanets other than through shifts in starlight distortions or subtle gravitational wobbles
- Good trap. First trap is that it's talking about all exoplanets and not only the ones that are far away from Earth, whereas the near ones use direct methods for measurement.
Ideally you should have already eliminated this choice by now, if not,
Second, we definitely need to use indirect methods to detect exoplanets that are far from Earth, and a couple of techniques used are starlight distortions and gravitational wobbles.
But do we know there's no other indirect method apart from these two that can be used for this measurement?
The argument only discusses a few examples using the phrase "such as", so it would be a strong hypothesis to rule out any others as it's not explicitly stated in the argument and hence, this is not an implied assumption. And if there does exist other indirect methods to detect reliable signal data, does the conclusion break? Don't think so, as the conclusion was made for all indirect methods not the only ones mentioned in the argument.
C. Reliable interpretation of signal-related data depends more on the characteristics of the host star than on the exoplanet itself.
- This might be true, but it’s not implied in any way by the given argument.
It could well be the case that the characteristics of the host star are one attribute required for communication, but other attributes of the exoplanet like its structure and atmosphere could be equally important for reliable communication.
D. Exoplanets orbiting stars with consistent emission patterns are less common than those orbiting stars with inconsistent emissions.
- Right on point! As we noted from our earlier statistics, exoplanets with inconsistent emissions i.e., 70 out of 100 are far greater than the other ones. So this is clearly an assumption of the argument.
If we negate this, say the ones with consistent emissions are more common, then exoplanets with consistent host stars would likely be in the majority, and the conclusion that "few exoplanets are likely to produce communication signals that can be consistently detected" would completely fall apart.
E. Some exoplanets orbit stars with stable emissions but still fail to produce reliably detectable signals.
- Sure, this might be true, but the argument doesn’t need it. Even if 5 out of the 20 stable ones failed to produce signals, there would still be few left, and the conclusion would still stand. This isn’t something the argument depends on but it’s just extra information.
Answer: D
24 Jan 2026, 03:20
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Therefore, few exoplanets are likely to produce detectable signals that can be consistently detected unless they are close enough to Earth to be observed directly. Doesn't this statement hint at the assumption that option A is the answer ??
