The roof
Maria Mitchell, twenty-nine, lives with her family over the Pacific Bank on Nantucket, where her father, William, is cashier. The family is Quaker. On 1 October 1847, from the roof of that home, she sweeps with a small telescope and finds a faint smear that is not on her charts.
She records it. Her father writes to William Bond at Harvard. The comet is real. It is faint. It is hers to have seen first, once the medal argument is done.
What the night was
This is not a new physics. It is looking, comparing, writing the time, and trusting that a smear off the map might be a world of ice on a long orbit. Most nights on that roof ended with nothing. This one did not.
Later she taught at Vassar and took students onto other roofs. The 1847 night remains a woman with a small telescope, a bank, an island, and a chart that was missing a line.