📅 7 January 1610
He recorded three small points near Jupiter, initially regarding them as background stars.
📅 7 January 1610
The positions of the lights were unusual enough to prompt repeated observations on later nights.
📅 7 January 1610
His first dated observations began the sequence that established satellites orbiting Jupiter.
📅 7 January 1610
A more powerful telescope made faint neighboring points visible; recognition of their orbits followed later.
