James Craig Watson was responsible for today’s first entry. 150 Nuwa was first spotted by him on October 18th, 1875, and is a large, dark, C-type, main belt asteroid in the Hecuba group.
Nuwa is about 146 km across, and takes a little more than 5 years to orbit the Sun. It is named after the Chinese goddess Nüwa, thought to be creator of mankind.
Our second rock today is 2060 Chiron, a 233 km wide cross between an asteroid and a comet, discovered on this day in 1977 by Charles T Kowal, and named after a centaur (half man, half horse) from Greek mythology. This particular centaur was known as the wisest of his race, and tutored the young Achilles.
Chiron was the first object to be discovered orbiting between Saturn and Uranus. Objects in this class are now known as centaurs.
1963 – Launch of Kosmos 20.
October 18th, 1989 saw the launch of the Galileo spacecraft, on its way to Jupiter. It was carried out of Earth’s atmosphere by the shuttle Atlantis (mission STS-34). Unusually for a craft headed to Jupiter, Galileo was first pointed in the direction of Venus. This was because the fastest way to get the probe to its target was to use the “gravitational assist” method of acceleration. After Venus, Galileo came back past Earth for a speed boost, before a rendezvous with asteroid 951 Gaspra (October 29th, 1991).
It was then able to slingshot past Earth a second time, adding more than 3 km/second to its speed, before a second asteroid encounter, this time with 243 Ida on August 28th, 1993. Jupiter was reached on December 7th, 1995, whereupon Galileo became the first spacecraft to park in orbit around the gas giant.
Galileo spent eight years in the Jovian system, and was deliberately destroyed on September 21st, 2003 by dropping it into Jupiter’s atmosphere.