 Greetings and welcome to the Introduction to Astronomy. In this week's Astronomy of Other Cultures, we are going to start looking at Chinese astronomy and introduce that topic. So let's take a look a little bit about early Chinese astronomy. Chinese records go back over 3,000 years, and they had many early star charts actually studied the circumpolar stars and focused on those. Now in Western astronomy, we tended to study the stars around the ecliptic or the path of the sun. So here we see a cultural difference in that many of the stars that were being looked at were those near the North Celestial Pole, which of course remained stationary in space. Now we have the very first star catalogue was Gan Di, and that was not the first catalogue in existence, but the first catalogue where the author was actually identified over 2,000 years ago. We also know that Gan Di may have observed the moons of Jupiter. Now the moons of Jupiter are normally not visible because they're too faint close to the relative brightness of Jupiter. However, if Jupiter is blocked out and the moons are at their greatest distance, it is quite possible they are bright enough to be seen with the naked eye. So there are thoughts that he actually was able to observe the moons of Jupiter long before Galileo saw them with the telescope. We also had another Chinese astronomer of the same time, Xi Shen, who gave us the earliest surviving record of sunspot observations. Again we generally attribute this to Galileo who saw them with the telescope, but very large sunspot groupings can be seen with the naked eye. Now normally you can't look at the sun, but at sunrise or sunset you can see this. So 2,500 years ago we do have records of early records of sunspot observations. They had a great understanding of eclipses and methods to be able to predict eclipses. And in fact a thousand years ago we had a Shen Kuo pictured here and this astronomer actually determined that the celestial objects had to be round and were not flat. So things like the moon and the sun were determined to be round objects. Now a lot of the Chinese observations, there were detailed observations of things like supernovae and in fact the supernova of 1054 which now leaves behind the remnant of the crab nebula. And we also see observations of Halley's Comet. Now these are just general comet observations pictured, but Halley's Comet was observed from its appearance in 240 BC. Now they did not know that the comets would recur, that was something that we did not learn about until much later. But they did have observations of these comets and you can see the comets noted here along with the different structures to the tails of the comet that were observed by astronomers in China thousands of years ago. So let's go ahead and finish up with our summary. And what we've looked at is that Chinese astronomy was very well developed even many thousands of years ago. We have star charts dating back about 3,000 years and also observations of sunspots, comets and supernovae. So that concludes this lecture on the introduction to Chinese astronomy. We'll be back again next week for another topic in astronomy of other cultures. So until then, have a great day everyone and I will see you in class.