Ancient astronomers saw Jupiter as a "bright, wandering" star" and they most likely associated it with the mythology of the time. Ancient Romans named the planet after the Roman god, Jupiter (Zeus in Greek mythology) and the astronomical symbol (see Figure 1) is a representation of the lightning bolt carried by Zeus (Crystal).
In 1610, Galileo Galilei made the first detailed observations of Jupiter (Harvey). He discovered Jupiter's four large moons (see Figure 2) Io, Europa, Ganymede, and Callisto (aka the Galilean moons) and documented their motions around Jupiter (Wikipedia). This was the first discovery of a center of motion not apparently centered on the Earth. It was a major point in favor of Copernicus's heliocentric theory of the motions of the planets (Jupiter"). .
main physical data/characteristics.
Jupiter is the fifth planet from the Sun and the largest planet in the Solar System (see Table 1). It has a mass one-thousandth of that of the Sun but is two and a half times the mass of all the other planets combined (Wikipedia). Jupiter is a gas giant and is classified as a Jovian (outer) planet, along with Saturn, Uranus, and Neptune. The gas planets do not have solid surfaces; their gaseous material simply gets denser the deeper you go. What we see when looking at Jupiter is the tops of clouds high in its atmosphere. Jupiter has a fast rotation - spinning on its axis approximately once every 10 hours. This fast rotation creates strong jet streams, smearing its clouds into bands across the planet. When viewed from Earth, Jupiter can get bright enough to cast shadows.
Table 1 Physical Data of Jupiter.
Volume: 1.43 x 1015 km3.
Equatorial Inclination to Orbit: 3.1 °.
Density: 1.33 g/cm3.
Angular Diameter: 29.8" " 50.1".
Surface Area: 6.14 x 1010 km2.
Average orbital speed: 13.07 km/s.
Mean Radius: 6.99 x 104 km.
Apparent Magnitude: -1.6 to -2.94.
Escape Velocity: 6.020 x 104 m/s.
Equatorial Surface Gravity: 24.
