Answer:
HERE IS THE COMPLETE QUESTION:
Astronomers who study planet formation once believed that comets—because they remain mostly in the distant Oort cloud, where temperatures are close to absolute zero—must be pristine relics of the material that formed the outer planets. The conceptual shift away from seeing comets as pristine relics began in the 1970s, when laboratory simulations revealed there was sufficient ultraviolet radiation reaching comets to darken their surfaces and there were sufficient cosmic rays to alter chemical bonds or even molecular structure near the surface. Nevertheless, astronomers still believed that when a comet approached the Sun—where they could study it—the Sun’s intense heat would remove the corrupted surface layer,exposing the interior. About the same time, though, scientists realized comets might contain decaying radioactive isotopes that could have warmed cometary interiors to temperatures that caused the interiors to evolve.1. The author suggests that the realization described in the final sentence of the passage had which of the following effects?
A. It introduced a new topic for study by astronomers interested in planetary formation.
B. It led astronomers to adopt a number of different strategies in trying to determine the composition of cometary interiors
C. It called into question an assumption that astronomers had made about comets
D. It cast doubt on astronomers’ ability to study the interior parts of comets. E. It caused astronomers to revise their account of the composition of the outer planets
The correct answer is:
A. It introduced a new topic for study by astronomers interested in planetary formation.
Explanation:
In the beginning of the text the author explains about the initial theoretical concept that the experts had about the comments. I was initially thought that comets were leftover material from the formation of the planets . Taking into account this information, it is possible to see that the new findings about the composition of comets is a new topic for astronomers.
