Question

before the invention of digital cameras, scientists had to rely on visual artists to capture fleeting natural phenomena such as eclipses. in 1918, astronomers commissioned painter howard russell butler to depict the total solar eclipse that would be visible over baker, oregon. one of butlers biggest challenges was having less than two minutes to capture subtle changes in light. to accomplish this, he worked in ten - to - twenty - second shifts and began by sketching the corona—the outermost layer of the sun’s atmosphere.
__________ back at his studio, butler relied on his sketches, notes, and memory to paint what he had seen. after receiving acclaim for his accurate and visually stunning work, he created images of three more eclipses in 1923, 1925, and 1932.
butlers time limit was particularly short; sometimes eclipses can last as long as seven and a half minutes.
butlers attention to detail served him well as he painted other majestic events, such as the northern lights.
butler had once studied physics and used his deep understanding of the principles of light throughout his work.
he then wrote down the colors he observed and drew an outline of any visible gases surrounding the eclipse.

Explanation:

To solve this, we analyze the context before and after the blank. Before the blank, Butler started by sketching the corona. After the blank, he is back at the studio using sketches, notes, and memory. We need a sentence that shows what he did right after sketching during the eclipse (before going back to the studio).

• The first option talks about the time limit of eclipses, which is not about what he did next.
• The second option is about painting other events later, not during the eclipse observation.
• The third option is about his physics knowledge, not the immediate next action after sketching.
• The fourth option ("He then wrote down the colors he observed and drew an outline of any visible gases surrounding the eclipse.") shows the next steps he took after sketching (noting colors, drawing gas outlines) before returning to the studio, which fits the sequence.

We need to find the sentence that logically continues the sequence of Butler's actions during the eclipse observation (before returning to the studio). The sentence "He then wrote down the colors he observed and drew an outline of any visible gases surrounding the eclipse." follows his initial sketching (as described before the blank) and precedes his studio work (as described after the blank), showing the next steps he took to document the eclipse. Other options either discuss unrelated topics (eclipse time limits, other paintings, physics knowledge) or do not fit the action sequence.

Answer:

He then wrote down the colors he observed and drew an outline of any visible gases surrounding the eclipse.