Graduate students Delia Marcus and Pedro Salazar explain that astronomy is the study of space and the physical universe, and it may be challenging to understand its appeal to young scientists. Marcus remarks, "What other branch of science gives you the chance to visualize the origins of the universe?" Salazar concurs, "We astronomers are at the forefront of understanding the very mechanisms that make the cosmos possible." To confirm their points, Marcus and Salazar interviewed several experts in the field, including author J.D. Matthews and astrophysicist Michael Davies, who agree with their assessment. Matthews comments, "Understanding how our own solar system works is just one piece of the puzzle. There are countless other solar systems like ours across the universe." Davies further elaborates, "This begs the question, when—not will—we find a similarly habitable planet like our own?"

Question

Question
Use the passage to answer the question.

Which word describes the tone of the last sentence of the passage?

(1 point)
Responses

worried
worried

formal
formal

optimistic
optimistic

assertive
assertive

Answer 1

The word that describes the tone of the last sentence of the passage is optimistic. The phrasing "when—not will—we find a similarly habitable planet like our own?" implies a hopeful anticipation of future discovery rather than a negative outlook.