I’ve also put together a quick animation that demonstrates how the moon rotates around the Earth. The Moon always keeps the same face facing towards the Earth (and so the same face pointing away). This down to two important facts.
1. The moon rotates on its on axis, it takes approximately 28 days to make one full rotation
2. The moon orbits around the earth. It takes approximately 28 days to make one full orbit.
In the animation below, I have coloured the moon to make it clearer. This is the view from above as it rotates.
As the moon rotates, it is also travelling around the Earth. The Moon has become locked into a pattern – the time it takes to orbit the Earth is the same as the time it takes to make one full rotation – approximately 28 days.
As you can see, as the moon travels around the Earth, it is also rotating. The Red/Yellow face is always kept facing towards the Earth. If we were standing on the Earth looking at the Moon we would only see the Red/Yellow face. We would never be able to see the Blue/Green face.
Want to build your own model solar system? Here’s a handy guide to work it all out to the correct scale. Simply put in the size of the Sun and the website will give you all the sizes and distances of the planets.
It’s the 40th Anniversary of the Apollo landings and there’s a lot of good stuff on the web as we hit the actual anniversary of the launch of Apollo 11 (in about 30 mins time in fact)
WeChoosetheMoon is an excellent recreation of the mission in real-time. With audio and video links to experience the launch as it happened.
You can also follow Apolloplus40 for live tweets (well, as-live)
The Big Picture continues its amazing series of images with a set of pics of Apollo 11. Some awesome images that are well worth storing for the next time you need to teach about the Moon.
You can run it automatically, and change the speed. or pause it and step through slowly. You can choose to view the whole thing with the sun at the centre, or to follow a particular planet around.
The controls at the side let you zoom in so you can see a few planets more closely. You can also make the planets bigger to make them easier to see on an IWB.
Another nice touch is that if you click and drag any planet, all the others will move in time with it.
This is a neat little tool to show how the planets orbit the Sun. You can see how some move faster than others and use the dates to calculate how long it would take some of the outer planets to complete one orbit. Visit the site now and have a play!
Another one of your questions was about Day, Night and Seasons. I’ll try and link to some good animations and guides about this that are already on the web.
The Earth is always lit from one side by the Sun. The side that is in shadow is in Nighttime, the side that is lit by the Sun is in Daytime. If you follow one spot on the Earth such as London, as the Earth spins it will eventually move from night into day and then later back into night time again. From where we are standing it looks like it is the Sun that’s moving instead.
To add to the confusion: The Earth is slightly tilted on its axis. This means at some times of the year, the Northern Hemisphere is tilted slightly towards the Sun (Summer) and at other times of the year it is tilted away from the Sun (Winter). At the Spring and Autumn Equinox the two hemispheres are neither tilted away or towards the sun.
In the winter the Sun rises later and sets earlier. We have short days and long nights. In the Summer the sun rises earlier and sets later, we have long days and shorter nights. At the Spring and Autumn equinox the length of day and night is equal (equi = equal nox=night)
Microsoft have finally released the public beta of their World Wide Telescope project, and I just had to write about it. It’s a must for anyone who has to teach about space, or just anyone interested in astronomy.
Basically, its Microsoft’s version of Google Earth/ Google Sky and if you’ve used the Google version in the past then you’ll pick this up very easily.
The software provides a virtual planetarium and lets you study the night sky with great detail. Some of the images are astounding. You can also switch the view to study planets and moons such as Jupiter and Io.
When looking at the stars, right clicking will bring up a star identifier which tells you the name of the star (if known) and some information about it. You can even link direct to the relevant wikipedia page.
Maybe a quick activity would be to search for their star sign (I looked up Aries) and find the names of the stars in the constellation. Maybe even find out how far away they are from Earth.
You can also point the camera downwards and study the Earth instead just like Google Earth, although not in as high resolution. A nice feature is the Earth at Night view which shows just where all the populated areas are. Interesting to use for Geography perhaps?
This is highly recommended and would be an excellent piece of software for anyone who has to teach about the Earth and space. Download it from here.
Firstly, it’s had to google this without getting lots of hits for classic Pink Floyd albums. Secondly, strictly speaking it’s the *far* side of the moon. It’s not always dark because sometimes it is facing directly at the Sun and is well lit.
Anyway, the question relates to the fact that Moon always keeps the same face facing towards the Earth (and so the same face pointing away). This down to two important facts.
1. The moon rotates on its on axis, it takes approximately 28 days to make one full rotation
2. The moon orbits around the earth. It takes approximately 28 days to make one full orbit.
In the animation below, I have coloured the moon to make it clearer. This is the view from above as it rotates.
As the moon rotates, it is also travelling around the Earth. The Moon has become locked into a pattern – the time it takes to orbit the Earth is the same as the time it takes to make one full rotation – approximately 28 days.
As you can see, as the moon travels around the Earth, it is also rotating. The Red/Yellow face is always kept facing towards the Earth. If we were standing on the Earth looking at the Moon we would only see the Red/Yellow face. We would never be able to see the Blue/Green face.
What happens when you drop a heavy object and a light object at the same time? Well they should hit the ground at exactly the same time. This is because the pull of gravity is the same on each one, and so they accelerate at the same rate.
On Earth it’s hard to visualise this since air resistance also gets involved – and so if you drop a hammer and a feather the feather floats down slower than the hammer.
On the moon, there is no air, so air resistance does not affect the result. One of the experiments carried out by the Apollo astronauts on the moon was to demonstrate a hammer and feather drop and as you can see, without air resistance both the hammer and feather hit the ground at the same time.
