Conclusion
Comets don't have their own light but reflect it from other light sources. A comet's mass is estimated by its brightness. Greater the mass - more light it would reflect off of itself. New revelation by the satellite probe: Haley's comet's material is composed of material which reflects the light many times LESS per unit mass than was previously thought.
Bunuel wrote:
Comets do not give off their own light but reflect light from other sources, such as the Sun. Scientists estimate the mass of comets by their brightness: the greater a comet’s mass, the more light that comet will reflect. A satellite probe, however, has revealed that the material of which Halley’s comet is composed reflects 60 times less light per unit of mass than had been previously thought.
The statements above, if true, give the most support to which one of the following?
(A) Some comets are composed of material that reflects 60 times more light per unit of mass than the material of which Halley’s comet is composed.
Passage doesn't inform us about other comet's materials. We can not be sure of this statement just from the information provided.
(B) Previous estimates of the mass of Halley’s comet which were based on its brightness were too low.
If it takes more Halley's material to reflect the amount of light that we've seen, then Halley's must be bigger than we thought. In other words, previous estimates were too low. We have to understand the causality here: ...the greater a comet’s mass, the more light that comet will reflect...
(C) The total amount of light reflected from Halley’s comet is less than scientists had previously thought.
The point of the stimulus is not that Halley's reflects less light than we thought. Rather, it reflected a certain amount of light, which, as it turns out, requires more Halley's material to reflect. Amount of light reflected is dependent on the mass, not the other way around. The causality mentioned above is important here.
(D) The reflective properties of the material of which comets are composed vary considerably from comet to comet.
We cannot be sure of this just from the information in the passage. No information regarding this.
(E) Scientists need more information before they can make a good estimate of the mass of Halley’s comet.
Since the only factor mentioned used in estimating the mass is brightness - which is correctly known now by the satellite probe, the mass could be easily determined. No more information should be necessary to make a good estimate of the Halley's comet's mass.
Hence, the
Correct Answer: (B)EDIT: Corrected the error. I was wrong in choosing (B) over (C). Thank you
Arro44 for the correct explanation. To read Arro44's detailed answer to this question click
here. (Don't forget to drop a Kudos while you are there.
)
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