 Greetings and welcome to the Introduction to Astronomy. In this week's Exploration of the Solar System, we are going to look at the Apollo 11 mission, the first successful landing of humans on the surface of our Moon. So here we see, first of all, the launch, which occurred on July 16, 1969, using a Saturn V rocket, a very large rocket here, to propel the very small payload at the very top, which contained the command module, which would take them to the Moon and back and also serve as their way to return through Earth's atmosphere, and the lunar module that would then land on the Moon. Now they landed on the Moon on July 20th and actually had the first step on the Moon on July 21st of 1969. The crew pictured here was Neil Armstrong, Buzz Aldrin, and Michael Collins, and they landed at a specific place in the Sea of Tranquility near what is called the West Crater. So we can see their landing site here, the Apollo 11 landing site off to the left-hand side over here, and the West Crater off over to the right-hand side of our image. So that is where Apollo 11 landed. Now the exploration of the surface took only a couple of hours. They spent about two hours on the surface of the Moon exploring, and we can see some of those images here, and here we can see lunar footprints, and this is the picture of Buzz Aldrin as taken by Neil Armstrong, and if you look closely in the visor, you can actually see the reflection of Neil Armstrong in the visor. So his own picture is there, so he actually took a picture of both of them at once, Buzz Aldrin there standing on the Moon, and of course himself reflected in the visor. Now they spent, I said, about two hours on the surface and did a number of different things including collecting samples. So samples about almost 50 pounds worth of material, more than 20 kilograms, that would been returned to Earth, so material that we could then study later on. They also set up a number of experiments. Here we see one of the experiments set up to measure seismic activity on the Moon, so we wanted to know what is the Moon active down below, and as we have earthquakes on Earth, we find out that yes there are moonquakes on the Moon, although they are much less intense than the stronger earthquakes that we get here on Earth. They also set up some lunar ranging experiments which could allow us to measure accurately the distance between Earth and the Moon by reflecting a laser off a reflector that was left on the Moon, and that still works to this day. Now they then left the Moon surface and they actually returned to the command module on July 21st. So here we see the Earth off in the distance there, so we can see our Earth in this image as well, and we see the lunar module as it heads back up toward the command module. So this image was taken by Michael Collins in the command module as the lunar module prepared for docking. So coming back up there and then the astronauts would transfer from the lunar module back into the command module in preparation for their return to Earth. The return to Earth would occur just a couple of days later on July 23rd, and they would then splash down in the Pacific Ocean. So here we see that as they're being recovered in the command module, which had a very strong heat shield at the bottom to be able to survive the trip through Earth's atmosphere, and return the astronauts safely then to Earth. So again, this was the first successful landing on the Moon and having humans actually walk on the Moon and bring back samples for future study. So let's go ahead and look at our summary here, and what we've looked at is Apollo 11 mission safely landed humans on the Moon's surface for the first time. It was our first direct study of another world, the first time humans had directly studied, not through robotic craft, not through just looking at things through a telescope, but actually directly studying another world in our solar system. And experiments were left on the Moon and samples were returned to Earth both for further study, samples for further study and experiments, some of which lasted for a short period of time, others which are still running today. So that concludes this lecture on the Apollo 11 mission. We'll be back again next time for another exploration of the solar system. So until then, have a great day everyone, and I will see you in class.