jan 3, 1610 - Galileo makes many different observations about the solar system, using his new telescope.
The moon is an irregular, rough body, not smooth as scientists thought.
The Milky Way is composed of many stars.
Jupiter has many small satellites that he named, "Sidera Medicea," after his favorite pupil.
He made observations about Saturn, sunspots, and the phases of Venus.
He publishes the results in the 1610 book, "Sidereus Nuncius." ("The Starry Messenger")