Observing the Moon

Learning Outcomes To identify the Moon’s principal features. To know the size of, and distance to, the Moon. To know the values of the Moon’s orbital and rotation periods, and explain why these prevent us from seeing the Moon’s ‘far side’.

To identify the Moon’s principal features. Bell Work Try to draw as accurately as you can the picture of the moon below.

Key Features of the moon… Sea of Tranquility, Ocean of Storms, Sea of Crises,Craters Tycho, Copernicus and Kepler, and the Apennine mountains

Mare Imbrium (Sea of Showers) This is the largest of the maria, a circular plain 1250km in diameter. Archimedes crater The Soviet spacecraft Luna 2 crashed near this crater in 1959. Oceanus Procellarum On this plain in 1966, Luna 9 became the first spacecraft to soft-land on the Moon. Mare Tranquillitatis (Sea of Tranquility) The site of the first Moon landing by astronauts (1969). Aristarchus crater This is the brightest crater you can see on the Moon. It lies within Oceanus Procellarum. Tycho crater This is a magnificent ray crater, 85 km in diameter. The impact which caused the crater sent debris flying and produced rays extending 1500 km.

Mini Review On your picture (or a copy of the moon image if you aren’t the best at drawing!) mark on and label some of the key features.

To know the size of, and distance to, the Moon. How far away is the moon?

Mini Review The moon is 384,400km away from _______. The moon is 3500km in ________

To know the values of the Moon’s orbital and rotation periods, and explain why these prevent us from seeing the Moon’s ‘far side’. Moon Rotation The Earth rotates in less than 24 hours and travels around the Sun over 365 days. The Moon orbits the Earth in 27 Earth days, 7 Hours, 43 minutes and 7 seconds (Approx. 27.3 days). A day on the Moon is also 27.3 of our days long. We see two full Moons 29 days apart as the Earth is also moving in space while the Moon orbits around it. The orbit and rotation period of the Moon are identical.

Construct your knowledge Try to find out on the internet why we can never see the ‘dark side’ of the moon

The moons far side The Moon has a synchronous rotation which means that from Earth only one side or hemisphere can be seen. The side we see is known as the near side. The side we cannot see is called the far side. We did not know what the far side looked like until the Soviet Luna 3 probe took pictures of it in 1959. Today the only humans to have viewed it are the Apollo astronauts. The far side has fewer Maria than the near side, it is more cratered. It is thought that the near side has a thinner crust and has had a higher amount of heat-producing elements. No radio interference from Earth can reach the far side and so it is a candidate for a future radio telescope on the Moon.

Mini Review In your books describe why you cannot see the far side of the moon.

Answer The Time that the Moon takes to REVOLVE [around the Earth's axis][ one month ] is the same amount of Time that It takes to ROTATE [around its own axis].

Apply your knowledge You are now asked to produce an information leaflet on the moon and everything you have discovered today. Try and remember all that you can before using the internet to add interesting fact, pictures etc.