MEO orbits between 2,000 and 35,786 km above sea level. Satellites have orbital periods less than 24 hours. Dominated by solar radiation pressure and Earth's albedo. Includes Van Allen radiation belts above equator
Galileo is a global navigation system created by EU through ESA. System aims to provide independent positioning without US GPS dependency. Project cost €10 billion, launched in 2016. Headquartered in Prague with operations centres in Germany and Italy
Galileo allegedly dropped unequal weights from Leaning Tower between 1589-1592. Viviani claimed experiments were conducted with professors and students. Most historians consider it a thought experiment rather than physical test. Galileo's earlier prediction was that same-material objects fall at same speed. Experiment disproved Aristotle's theory of gravity
Galileo studied medicine in Pisa before discovering his interest in mathematics. He became professor at Padua University, teaching astronomy until 1610. His hydrostatic balance invention brought him recognition in 1586
Galileo improved his telescope design after hearing about Dutch perspective glasses in 1609. The telescope consisted of a main tube with separate housings for objective and eyepiece lenses. The objective lens was convex, 37mm in diameter, and formed a real, inverted image. The eyepiece lens was concave, 22mm in diameter, and created a virtual, upright image. The telescope could magnify objects up to 21x
GNSS is a worldwide network of satellites providing geolocation and time information. Satellites orbit at altitudes between 20,000 and 37,000 kilometers. Trilateration uses signals from at least four satellites for precise positioning