A student is writing an essay about nineteenth-century astronomy.
[1] In 1845, Irish astronomer William Parsons completed construction on the Leviathan of Parsonstown, a reflecting telescope with a six-foot aperture that was the largest in the world at the time. [2] With this massive instrument, Parsons observed and sketched the spiral structure of the Whirlpool Galaxy, a nebula then known as M51. [3] Prior to this discovery, astronomers debated whether nebulae were merely nearby clouds of gas or distant, independent 'island universes' consisting of stars. [4] The detailed drawings produced by Parsons provided crucial visual evidence that suggested a distinct, organized structure. [5] However, because the Leviathan's metal mirror was highly susceptible to tarnishing in the damp Irish climate, Parsons could only use the telescope on a few clear nights each year. [6] It took several decades of further observation with improved instruments to conclusively resolve the debate in favor of the island universe theory.
The writer is considering deleting Sentence 5 from the paragraph. Should the sentence be kept or deleted?
- Kept, because it explains the operational limitations that prevented Parsons's observations from immediately resolving the astronomical debate.Answer
- BKept, because it details the structural components and metallurgical innovations required to build the world's largest telescope.
- CDeleted, because it interrupts the paragraph's focus on astronomical debates by introducing irrelevant details about the Irish climate.
- DDeleted, because it contradicts the earlier claim that the Leviathan of Parsonstown was the most advanced and successful instrument of its era.