Saturday, May 12, 2012

Super Moon and etc

A week ago there was quite a bit media hoopla about super moon. I know that super moon is a full moon. What is the phenomenon super moon different from a usual full moon?

Moon phases

Moon has eight phases which are defined based on its appearance to people on earth:

1. new moon - at this phase moon is approximately aligned between sun and earth. we actually can not see the moon
2. Waxing crescent - this is when we see the crescent moon growing - waxing means growing
3. First quarter - though the phase is named first quarter - we see a half moon at this stage
4. Waxing Gibbous - this is the phase that moon appearance changes from half moon to full moon - what we see is more than half moon. Gibbous means
5. Full Moon (2nd quarter) - we see the full moon. This is when the earth is aligned between moon and the Sun
6. Waning Gibbous - this when the moon appearance shrinks from full moon to half moon. Waning means shrinking
7. Third Quarter - it is half moon again
8. Waning Crescent - this is when we see the crescent moon shrinking - until it disappears from view - we return to new moon.

New/Full Moon happens when Sun, Earth and Moon align approximately. The reason that the Moon does not block the Sun at new Moon phase, and the Earth does not block the Sun at full Moon phase, is that the moon's orbit about the earth is about 5 degrees off from the earth-sun orbital plane.However, at special times during the year, the earth, moon, and sun do in fact "line up". When the moon blocks the sun or a part of it, it's called a solar eclipse, and it can only happen during the new moon phase. When the earth casts a shadow on the moon, it's called a lunar eclipse, and can only happen during the full moon phase. Roughly 4 to 7 eclipses happen in any given year, but most of them minor or "partial" eclipses. Major lunar or solar eclipses are relatively uncommon.

The Moon-Earth-Sun forms 90 degree angle at 1st quarter and 3rd quarter.

Super Moon

What is the difference between super Moon and other full Moon?

Due to the moon's egg-shaped orbit, our natural satellite is at perigee—its closest approach to Earth—about once a month. The term "supermoon" was coined in 1979 to describe a full moon that coincides with perigee. (Apogee, when the moon is farthest from us, also occurs on a roughly monthly schedule.)

On May 5, last Saturday, the moon was 221,801 miles (356,955 kilometers) from our planet—and just minutes away from of the official full moon phase, at 11:35 p.m. ET. "As a consequence, this translates into it appearing as much as 16 percent bigger and 30 percent brighter than other full moons of 2012"

Watching Super Moon

Around 9:30pm May, 5, Nicholas was about to go to bed when his Mom reminded everyone "super Moon, anybody?". Yeah! The whole family rushed out of the front door.

It was a clear night, with light breezy. It felt really nice outside. The super moon was right in front of us in the Southeast sky, over our cross street neighbor's roof. It was quite a sight, the Moon was full with a Halo around it due to the wind. 

We stayed outside for a minute or two to enjoy the weather and the Moon. Then we decided to take a picture of it. It was not easy - our advanced Nikon camera could not record the real image in the sky, somehow, the camera automatically light up the sky in the photo; our "aim-and-shot" Sony actually could capture the Super Moon well because it has a moon setting.

The exposure time for taking the picture was long - I could not hold my hand steady and the moon was blurred in the pictures; Lily gave it a try and she got a really good picture, as good as the one I took later using a tripod!!

A fascinating interlude for an otherwise routine day!!


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