Astronomy Picture of the Day . A Violet Moon . ... The view looks down on the Moon.. Tonight: A Blue Moon . ... In fact, the modern usage of the term "Blue Moon" refers to the second Full Moon in a single month. ... A Dust Jet From Hale-Bopp . ... Approaching the inner Solar System, comet Hale-Bopp's icy nucleus is heated by sunlight, accelerating its production of dust and gas. ... Huck Finn's New Sky View . ... Brittany, age 7, and D.J., age 12, ponder this question over dinner one evening. ...