"Altissimam planetam tergeminam observavi."
I have observed that the most remote planet is triple.
In explaining more fully the nature of his observation, Galileo remarked that Saturn was not a single star, but three together, nearly touching one another: he described them as having no relative motion, and as having the form of three o's, namely, oOo, the central one being larger than those on each side of it.
Although Galileo had announced that nothing new appeared in the other planets, yet he soon communicated to the world another discovery of no slight interest. The enigmatical letters in which it was concealed, formed the following sentence:--
Hitherto, Galileo had observed Venus when her disc was largely illuminated; but having directed his telescope to her when she was not far removed from the sun, he saw her in the form of a crescent, resembling exactly the moon at the same elongation from the sun. He continued to observe her night after night, during the whole time that she could be seen in the course of her revolution round the sun, and he found that she exhibited the very same phases which resulted from her motion round that luminary.
Galileo had long contemplated a visit to the metropolis of Italy, and he accordingly carried his intentions into effect in the early part of the year 1611. Here he was received with that distinction which was due to his great talents and his extended reputation. Princes, cardinals, and prelates hastened to do him honour; and even those who discredited his discoveries, and dreaded their results, vied with the true friends of science in their anxiety to see the first wonder of the age.
In order to show the new celestial phenomena to his friends at Rome, Galileo took with him his best telescope; and as he had discovered the spots on the sun's surface in the month of March, 1611, he had the gratification of exhibiting this new wonder to his admiring disciples. He accordingly erected his telescope in the Quirinal garden, belonging to cardinal Bandini; and in April, 1611, he exhibited them to his friends in many of their most interesting variations. From their change of position on the sun's disc, Galileo at first inferred, either that the sun revolved about an axis; or that other planets, like Venus and Mercury, revolved so near the sun as to appear like black spots when they were opposite to his disc. Upon continuing his observations, however, he saw reason to abandon this last opinion. He found, that the spots must be in contact with the surface of the sun; that their figures were irregular; that they had different degrees of darkness; that one spot would often divide itself into three or four; that three or four spots would often unite themselves into one; and that all the spots revolved regularly with the sun, which appeared to complete its revolution in about twenty-eight days.
