In his observatory, an astronomer is visited by the king accompanied by his jester. Through the eyepiece of a telescope, the astronomer shows Jupiter, the planet, to the king who is enthusiastic and asks the astronomer more details about it. The astronomer then takes a big book in which are screened flowing images of the star-spangled sky and of a rope ladder climbing to the Moon, Saturn, and Jupiter. More and more moved, the king goes with the astronomer on a balcony and, with the help of a telescope, he observes an anthropomorphic round Moon, a lunar crater with smoke and flames coming out, Saturn and Jupiter. After having retired to his bedroom, tried by so many emotions, the king falls asleep and dreams. He climbs on a ladder to the stars and reaches Jupiter. The reception waiting for him is very far from being friendly… This is a wonderful short film created by the amazing mind of Segundo de Chomón, the Spanish film-maker. It has at least four striking views, with an excellent artistic and narrative subject. The childish eyes of the maker lead the spectator to an oneiric world where an explorer needs only a ladder to get to the stars and the planets look human. Someone could reproach him with his lack of sophistication, but undoubtedly nobody can deny his artistic and technical value and merit (noticing the year when the film was made). As in Méliès’ Voyage dans la Lune, the leaving/approaching effect is suggested by a circle with king becoming small/big in its centre. The film is also known with the title Une excursion sur Jupiter and with the title Rêve de l’astronome, the latter being wrong.