There is some evidence that the youngest known supernova in our galaxy, G1.9+0.3, occurred in the late 19th century, considerably more recently than Cassiopeia A from around 1680. Neither was noted at the time. In the case of G1.9+0.3, high extinction from dust along the plane of the galactic disk could have dimmed the event sufficiently for it to go unnoticed. The situation for Cassiopeia A is less clear; infrared light echoes have been detected showing that it was not in a region of especially high extinction.