Galileo’s Last Rendezvous
...flyby of Amalthea. Instead, the spacecraft recorded high-speed science data on its tape recorder. Also this is where Galileo experienced its most intense magnetic and radiation environment it has ever faced throughout its entire trip. Galileo flew by Amalthea, passing one hundred and sixty kilometers above its surface. When they passed mission engineers hoped to measure how the moon’s gravity alters the course of the spaceship. Hopefully this information will help them find the mass and overall density of Amalthea. The measurements collected should help determine whether the development of Jupiter’s moon’s paralleled that of the planets around the Sun. Galileo has made more than 30 flybys of other Jovian moons, including Europa and Io, but never Amalthea. Knowing Amalthea's density might help pin down whether the origin of moons around Jupiter resembled the origin of planets around the Sun. The Sun's interior planets Mercury, Venus, Earth and Mars are rocky worlds much denser than the gas and ice planets from Jupiter on out. Likewise for Jupiter's four large moons Io, the innermost, is mainly solid rock and iron, while Ganymede and Callisto, the two outermost, are mixtures of rock and ice, and Europa completes a grade in between. After passing by Amalthea, Galileo will pass through Jupiter’s gossamer ring. This is to find out the masses and velocities of dust particles. Then Galileo will enter the inner Jovian magnetosphere. This is a great charged-particle environment and here the spacecraft will try to survive. Galileo will come closer to Jupiter than it ever has before. It will be dipping to within 70,000 km of Jupiter’s cloud tops. This radiation data will be vital for designing future missions to Io and Europa. These places are constantly bombarded by magnetospheric particles. Galileo has functioned in orbit more than three times longer than its originally planned mission. The Galileo spacecraft is still h...