The lunar surface gravity is only 0.16 (one sixth) that of Earth and the Moon orbits the Earth at 384,400 km/238,855 mi. Arising in the East, it is seen to progress West across our sky, but takes 27.32 days (the sidereal month) to orbit Earth. On its sunlit side, temperatures reach 1100C/2300F, but during the 2 week lunar night the surface temperature drops to -1700C/-2740F. It spins on its axis with one side permanently turned toward Earth, as a coincidence of its own rotational time. The side of the moon that faces us is one that has enchanted man since the dawn of time. It is been described as many things from a smiling face to a lump of cheese. Sadly, the Moon has no atmosphere or water and is not made of cheese (sorry Gromit, no cheese!).
A further remarkable coincidence causes phenomena that have struck terror and awe in mankind’s minds as well as intense curiosity; that of lunar and solar eclipses. It so happens that the ratio of apparent size to distance of the Moon is roughly equal to that of apparent size to distance of the Sun and when the Earth passes between the sun and the full moon we see the eerie sight of the moon shadowed by us. More rarely, when from our vantage point, the Moon passes between the part of the Earth where we are standing and the sun, we witness those breath-taking moments of a total eclipse. Such occurrences have been cherished by astronomers as they afforded an opportunity, otherwise not available, to study the Sun’s corona and massive solar flares.
The moon is in an elliptical orbit around the Earth, so over time it seems to get smaller and bigger when observed from Earth. When the Moon is closest, the Moon is sometimes referred to as a Supermoon. A Supermoon occur about once every 14 full moons and coincidence of a full moon or a new moon, resulting in the largest apparent size of the lunar disk as seen from Earth.
The lunar surface which faces us is illuminated in a cycle of phases and called waxing and waning. This effect is caused by its orbit, which turns the side of the moon facing us away from the sun every 29.53 days. Waxing is period from new moon when the surface is in full shadow to full moon when the surface is fully illuminated. Waning is the cycle back to new moon.
The Moon's rocky composition, with a surface heavily scarred by meteorite impacts, with some craters up to 240 km/150 miles across, has made man’s imagination run riot, including latter- day desires for mineral extraction. Rocks brought back by astronauts indicate that the Moon is 4.6 billion years old and therefore about the same age as Earth. The origin of the Moon is still open to debate.
Neil Alden Armstrong (5 August 1930 to 25 August 2012) was an American Astronaut who became the first person to walk on the Moon. He flew in spacecraft, Apollo 11, which landed at 2.56 UTC, July1969 and then stepped from its lunar module onto the Moon’s surface. He was followed only minutes later by Buzz Aldrin. The crew aboard Apollo 11 were Neil Armstrong, Edwin"Buzz" Aldrin and Michael Collins. Armstrong famously said:-"That's one small step for a man, one giant leap for mankind", when he first set foot on the lunar surface. Apollo 17, in December 1972, was the last manned mission to the Moon, and crew member Harrison Schmitt became the last person to step onto the Moon whilst Eugene Cernan was the last person to step off of the Moon. Although all this may soon change, when in the next round, with other countries pick up the baton.
Much of our information about the Moon has been derived from this and other photographs and measurements taken by US and Soviet Moon probes. A lot of information was also gathered thanks to the geological samples brought back by US Apollo astronauts, and from experiments set up by the US astronauts from the 1969 to 1972 Apollo program.
Did you know that the Moon affects our seas and oceans? Changes in water height on our coastlines are the effect largely caused by gravitational forces; due primarily to the proximity of the Moon to the Earth but combined with the Sun's gravitational attraction on the World's seas and oceans. The resultant ebb and flow we know as Tides. It was an English physicist and mathematician called Sir Isaac Newton PRS MP who was the first person to explain tides as the product of the gravitational attraction of astronomical masses. To find out more about tides, please click on here.
If you like space, why not take a look at our Meteor Shower Calendar page and find out what natural firework displays could be taking place above us tonight? Click here to take a look!
To find out about how the Moon affects our lakes, Seas and Oceans please click on here.
Click on the logo to go to the website
Liverpool Museum - The World Museum (Liverpool) was opened on 18 October 1861 and houses a range of extensive collections covering subjects from archaeology, ethnology, natural and physical sciences. Special attractions at the museum include the Natural History Centre and a Planetarium.
Liverpool Astronomical Society - The society is the oldest amateur astronomical society in the world, and was founded in 1881. The society’s aims are the same as when it was formed and they always welcome new members.