... Comet McNaught Becoming Visible to the Unaided Eye . ... Credit: Jose Francisco Hernandez ( Altamira Observartory ) Explanation: A new comet is brightening and is now expected to become visible to the unaided eye later this month. ... Although predicting the brightness of comets is notoriously difficult, current estimates place Comet McNaught as becoming visible to unaided northern hemisphere observers in late June, before sunrise, and in early July, after sunset. ... The Iron Tail of Comet McNaught...