21st April

On this day in 1702, Maria Winckelmann became the first woman to discover a comet. Her husband Gottfried Kirch wrote:-
Early in the morning the sky was clear and starry. Some nights before I had observed a variable star, and my wife wanted to find and see it for herself. In so doing she found a comet in the sky. At which time she woke me and I found that it was indeed a comet ... I was surprised that I had not seen it the night before.
In fact Kirch claimed the discovery for himself and did not give the above account until 1710.