The Moon looks Bigger – The Moon Apogee & Perigee

The Moon

Since the birth of human, they have always wondered what the Moon is, why it is like this and what is the significance of Moon. The Moon, the most closest celestial object that could be seen with naked-eye is at an average distance of 384, 401 Km from our home Earth.

Humans have used Moon as a source of light at night during Full Moon. Islamic year is based on a complete cycle of Moon on its orbit. The word ‘month’ comes from the word moon. We as a human have always thought ourselves as the only living being in this vast universe. We humans feel lonely, but due to the presence of Moon, we get relieved that we have a neighbour. And yes we can see it with our naked eye.

Moon Features

Some people see ‘Man in the Moon’. A normal person when see a Full Moon can see a Man’s face on the Moon. The dark patches makes such figure. The dark patches has its own history and its creation is long way back. The Moon has dark patches and light patches. The dark patches on the Moon seems to us like simple patches. The ancient Astronomers believed that the dark patches on Moon are like the oceans on the Earth and this is why they called the dark patches as “Mare” pronounces “MAH-ray”. But they are oceas of congealed lava that came out beneath the surface of Moon after the impacts of ruthless Meteorites. The craters we see on the Moon were also created by the impact of Meteories. The patches along with the craters and high land areas on the Moon makes Moon an interesting object of observation.

Significance of the Moon

In our Solar System, other planets have their own Moon(s). Jupiter and Saturn has more than 60 moons, but none of them are the size of our Moon as compared to the size of the Planet. The significance of our Moon is that it raises tides in Seas and Oceans on the Earth. There is cultural and religious significance as well. Finding New moon is an interesting and amazing activity and has a significance that is start of a month.

The Unique Moon

The beauty of Moon is that anyone can observe it without any equipment. A beginner Astronomer would always love to see the Moon as it is the most closest and biggest celestial object that can be seen with naked-eye. The curiosity increases when we know that the Moon offers different features for observation in different phases. Most of the children are obsessed by Moon due to its presence over the year in the night sky. A Binoculars can show the most prominent features on the Moon. A Telescope is required for serious observation when one wants to study its features, patches and prominent regions in detail.

Phases of the MoonPhases of the Moon (Source: http://www.nhn.ou.edu/~jeffery/astro/astlec/lec003.html)

Amazing Fact – You Only see One Side of the Moon

There is an amazing fact about Moon is that we always see one side that is the ‘near side’ although it is a spherical object. The other side known as the ‘far side’ is always on the back side. The reason is that the Earth’s gravity have caused the Moon to rotate on its own axis in exaclty the same time as it takes to orbit the Earth. Since the effect of orbiting and rotating is cancelled out, its always turned towards us.

Moon Apogee and Perigee

The Moon has a orbit which is not completely circular and so is elliptical. At one end, the Moon is at its farest from Earth with a distance of about 406,697 km (252,722 miles). This is called ‘Apogee’. At the other end, the moon comes closest to Earth at a distance of about 356 410 km (221 473 miles). This is called ‘Perigee’.

Perigee is of our interest as this is the time when Moon is closest to Earth and since it is closest, its apparent size increases to 10% to 14%. We can say that Zoom has increased without using any equipment. The Sun’s reflected light from the Moon as result increases and so is the tidal effect on Earth. To give a comparison between the appranet sizes of Moon at Apogee and Perigee, see the below picture.

The Phenomenon: Moon Apogee and PerigeeThe Phenomenon: Moon Apogee and Perigee (Source: http://www.fourmilab.ch/earthview/moon_ap_per.html)

The Science behind the Phenomenon

This phenomenon is occurs few times a year and  can be easily observed. One has to observe the Moon constantly and regularly every month to feel the actual difference. Even if you don’t, you will feel a slight difference on the Full Moon when it is on Perigee. 2 years back, I was going back to my home after Sun Set when there was Super Full Moon (yea got the point, the Moon was closer to us and so in Perigee). I heard some layman saying “Today, the Moon is looking bigger”.

Moon Apogee and Perigee Chart – 2012

Moon Apogee Perigee ChartMoon Apogee Perigee Chart

 

Abubaker Siddiq Shekhani

Abubaker Shekhani is an IT Entrepreneur and Full Stack Developer. He is the co-founder and the Developer behind Mytabeeb, a health care solution. He has worked for 5 years in Microsoft Dynamics AX space with Techno-functional role and glad to be one of few Microsoft Dynamics AX developers/consultants in Pakistan. He is TEDx speaker and likes to speak in public. He is an Amateur Astronomer and Astrophotographer. He is the founding member of Karachi Astronomers Society. He can be reached at me@abubakershekhani.com.

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