Question 144·Hard·Inferences
In a set of recently digitized letters dated 1896–1898, members of a British amateur astronomical society describe three minor lunar craters—Haver, Lyttel, and Crestwell—by the very names that first appeared in any formally published lunar atlas in 1923. None of the letter writers mention visiting professional observatories, and surviving records show that the small refracting telescopes they owned could not have resolved those craters in sufficient detail to warrant naming them. Barring the unlikely possibility that several independent observers invented the same names for the same features, these facts most strongly suggest that _____.
Which choice most logically completes the text?
For inference completions, list the passage’s hard constraints (dates, stated limitations, and anything the author labels unlikely). Then pick the option that explains all constraints with the fewest extra assumptions. Be wary of choices that rely on new speculative claims (misdating, hidden motives, vague usage) that the passage doesn’t point to.
Hints
Focus on what needs explaining
The key puzzle is the timing: the letters use crater names decades before those names appear in a formally published atlas.
Use the equipment limitation
The passage says the amateurs’ telescopes couldn’t resolve the craters in enough detail to justify naming them from direct observation. So look for a source of the names other than their own observations.
Prefer the explanation with the fewest new assumptions
A strong inference fits all the stated facts without adding extra unsupported claims (for example, that the letters were misdated or that the names were used only loosely).
Step-by-step Explanation
Pull the constraints from the passage
Key facts:
- The letters are dated 1896–1898.
- The names Haver, Lyttel, and Crestwell first appear in a formally published lunar atlas in 1923.
- Records indicate the amateurs’ small refractors could not resolve the craters in enough detail to justify naming them from direct observation.
- They did not report visiting professional observatories.
- The passage treats independent coinage of the same names for the same features as unlikely.
So we need an explanation for how the amateurs had those specific names decades before formal publication.
Identify what a strong completion must do
A logical completion should explain early access to the exact names while fitting the stated limitations:
- Not based on the amateurs’ own detailed observation.
- Not depending on an unlikely coincidence.
- Ideally involving some pathway by which the names existed before 1923 even if they were not yet formally published.
Evaluate the alternatives for support vs. speculation
Compare each choice to what the passage actually supports:
- A direct pipeline from professional cartographers (drafts, correspondence, informal sharing) neatly explains early access to specific names without requiring observation or coincidence.
- Claims about misdating the letters, professionals adopting amateur names, or the names being used only “loosely” are possible, but the passage provides no particular evidence for them; they introduce additional assumptions beyond what the text points toward.
Select the choice most strongly suggested by the evidence
The completion that best accounts for all constraints with the fewest extra assumptions is:
the amateur astronomers had access to unpublished material or informal communications from professional lunar cartographers.