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The Moon for Southern Hemisphere Beginners
.....Answering those Tantalising Questions.....
• What are the Moon Phases?
Viewed from The Southern Hemisphere
(but NOT to scale!)
The diagram above-left shows the Moon Phases (how the Moon's light appears to us as we view it from Earth). It shows the Sun and how it shines on the Moon and the Earth, as viewed from the Southern Hemisphere. Imagine that the Earth is "tipped on its end" so that you are looking at the South Pole directly in the centre of the Earth. The monthly chart at right shows which side of the Moon is alight at each different quarter, viewed from New Zealand (the dates may be one day out from other places because we are near the dateline). Both the northern and southern hemispheres of the Earth can see the Moon. However, the southern hemisphere sees the Moon "upside down" from how the northern hemisphere sees it. You can see how New Zealand views the moon when you view the movie "Lord of the Rings"!
The Moon's appearance changes from being a "New Moon" to a "First Quarter Moon" then to a "Full Moon" and on to "Third Quarter Moon", as it makes a full circle in its rotation around the Earth. It takes approximately 27.3 days (called a "sidereal month") to orbit the Earth but because the Earth is constantly moving in its own orbit around the Sun, it takes approximately 29.5 days to go through a full set of Moon phases (called a "synodic month"). The light of the Moon is only the reflection of the Sun's light upon it, as it has no light of its own.
The Moon travels eastward around the Earth. However, as it does so, it keeps only one side (and always the same side, of course) facing the Earth. So, although we see the Moon go into increasing shadow as it turns away from the Sun during it's cycle of phases (which takes 29.5 days), we are still seeing the same side of the Moon.
When it is a "New Moon" phase, we on Earth cannot see the Moon because the Sun is shining only on the other side of it (see the diagram above).
Apart from the main Moon phases, the Moon is referred to as in "waxing crescent" which is when it is approaching from New Moon to First Quarter and "waning crescent" which is when it is phasing from Last Quarter to New Moon. It is in "waxing gibbous" between First Quarter and Full Moon and "waxing gibbous" when it is between Full Moon and Third Quarter.
That is The Acorn Tree Oracle's explanation of what causes the "Moon Phases". (Now, isn't that clear as mud?!)
(don't get it mixed up with the phases diagram above, which is simply showing the Sun shining on the moon)
Both the Moon and the Earth turn anti-clockwise.
The Moon revolves around the earth in the same direction and same amount of time, that it also takes for it to rotate (27.3 days). This results in the Moon always keeping the same side turned toward the Earth and the other side turned away from the Earth. It is called "synchronous rotation". The side turned away from the earth is called the moon’s "dark side", even though it is actually lit up for half of the time. It's just that we can't see it from here.
If the Moon did NOT rotate, we would be able to see all its sides, gradually, as we proceeded through the month.
see Moon Phases diagram above).[note: click your back button on your browser to return to this spot.] This is able to happen because the Moon orbits at a slight angle from the Earth's orbit around the Sun. Consequently, the Sun's rays can zoom past the Earth and shine on the Moon!:) ... except during an eclipse of course!
A Total Lunar Eclipse is when the Moon is completely overshadowed and it becomes very dark or blood-like in colour. Partial eclipses, when the Moon is not so completely in the shadow of the Earth, may not be so obvious. The next Total Lunar Eclipse, visible from New Zealand, is on the 28th August, 2007.
In the Bible, there is reference to when the Moon will become like blood. This could possibly refer to a Total Eclipse of the Moon when the events which are described in this Bible passage, happen.
You want to see a pic? OK, have a look at the NASA photo taken during the Apollo 16 mission, here.
Why is the Moon in the Northern Hemisphere upside down from how it looks here in the Southern Hemisphere?:The Moon orbits near the equator of the Earth. In the southern hemisphere, we're standing on the opposite side of the globe from the "northerners", so we are "upside down" from each other! So we see the Moon from a completely different vantage point (ie "upside down"!). In fact, we in the southern hemisphere view most of the stars quite differently than from the northern hemisphere.
Does this mean that the moon looks smaller if it is farther away? Yes, it does. A full moon near perigee looks a lot bigger and brighter than a full moon near apogee. Anything which is closer looks larger and that is how it is with the moon.
Apogee and perigee for the month of July 2002, for example, was as follows:
Perigee: July 15, 0146hrs (1.46am) : 367,851 km away from earth.
In 2002, the moon was at its closest perigee for the year on February 28th. It was at 356,897 kms.
here, at NASA's Thursday Classroom. Maybe the real test will be when we can get on board a spacecraft which will take many of us there, just like we can go to another country. But of course, that's a little way in the future yet as there are a lot of hurdles to jump first (like the Van Allen radiation belts!).
Mars is likely to be the planet next colonised by our species but the Moon could be a drop-off base also. Science fiction may come to life!
Ask The Oracle about the Moon
Except animated moon which is courtesy of Jo's World