On October 26, 1956, the lunar astronomer Dinsmore Alter noted some blurring of the rilles on the floor of Alphonsus in the photographs he took in violet light.
Den 26. oktober 1956 observerede astronomen Dinsmore Alter nogen utydeligheder i rillerne i bunden af Alphonsus på nogle fotografier, han optog i ultraviolet lys.