Tales from the Darkside (1984)

S2E13 Comet Watch

Englebert Ames, an astronomer, is captivated by Hailey's Comet when he receives an unexpected surprise: Sir Edmond Hailey appears before him. It turns out that Hailey has been traveling on his comet all this time, trying to escape Sarah, a woman whose obsessive love drives her to relentlessly pursue him.