The Moon has an iron/nickel core, similar to Earth's, but smaller. The temperature on the Moon can range from -250F to +250F. The lunar atmosphere, what little there is of it, is comprised of Helium, Neon, Hydrogen, Argon, Methane, Ammonia, and Carbon Dioxide. These were measured by the Apollo mission teams during night conditions. Measuring the amounts during daytime was difficult, due to (according to NASA) "heating and outgassing of Apollo surface experiments". Once in a while, a small moonquake will shake the Moon, causing gas to escape from the fissures that are formed. Some scientists believe we should call the Moon a planet, since it is more like a planet than a Moon. Pluto's moon, Charon, is also in that same category, and some call Pluto and Charon a "double planet system." Did you know that there are trees here on Earth that grew from seeds taken on a Moon mission? During the Apollo 14 mission, astronaut Stuart Roosa took a bunch of seeds with him. When the mission was over, the seeds were germinated on Earth and planeted across the country. The trees that grew from them are referred to as "Moon Trees."
Think the Moon is our only satellite? That may not be true. Scientists have found an asteroid that is possibly orbiting our Earth! They have named this 5 km rock Cruithne, and its orbit takes 770 years. Another fun fact is that the moon is actually egg shaped, with one of its ends pointing at us, so that it appears round.
The Moon is slowly moving away from us, as it steals some of our energy. When it formed, it is estimated that it was only 22,530 km away from the Earth! Today, the Moon is over twenty times that! What will happen to the tides, and the Earth, when the Moon is so far away that it looks like a star to the naked eye?
Many planets have moons, but none fascinate us more than our very own. The cratered rock has mystified us since we began to look skyward and many superstitions have been written over time. Sioux Tribes called The Moon "The Old Woman Who Never Dies", The Iroquois called it "Eternal One", and Egyptians called the Moon the "Mother of the Universe".