On March 26, 1926, at his aunt’s farm in Auburn, Massachusetts, Clark University Physics Professor Robert H. Goddard — who received a master’s degree from Clark in 1910, and a doctorate in 1911 —launched the first liquid-fueled rocket. He had been performing experiments on liquid-fueled rockets since 1921 and successfully created an engine for one in 1923, steadily improving on the design and testing it in static racks in his Clark lab.

But Goddard’s work started much earlier — he first envisioned space travel as a 17-year-old in Worcester, 24 years before those static tests.

Goddard was a compulsive diarist. On October 19, 1899, he noted that he “trimmed [a] large cherry tree,” but he later noted that the day was transformative.

In “Material for an Autobiography” (1927), he wrote:

On the afternoon of October 19, 1899, I climbed a tall cherry tree at the back of the barn, on a plot where I had visions of some kind of frog-hatching experiments, and, armed with a saw which I still have and a hatchet, started to trim the deal limbs from the cherry tree. It was one of the quiet, colorful afternoons of sheer beauty which we have in October in New England, and as I looked toward the fields at the east, I imagined how wonderful it would be to make some device which had even the possibility of ascending to Mars, and how it would look on a small scale, if sent up from the meadow at my feet.

It seemed to me then that a weight whirling around a horizontal shaft, moving more rapidly above than below, could furnish lift by virtue of the greater centrifugal force at the top of the path,” he continued. “In any event, I was a different boy when I descended the tree from when I ascended, for existence at last seemed very purposive.

October 19 was of such significance to Goddard that he christened it “Anniversary Day,” and made some reference to it in his diary almost every year.

Robert Goddard’s papers, including diaries from 1898 to 1945, are housed in Clark University’s Archives and Special Collections.