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Supermoon November 14, 2016

November 14 presents the moon’s closest encounter with Earth in over 68 years, since January 26, 1948. The full moon on November 14, 2016, will feature the closest full moon (356,509 kilometers) until November 25, 2034 (356,448 kilometers).

What is a Supermoon?

A supermoon is the coincidence of a full moon or a new moon with the closest approach the Moon makes to the Earth on its elliptical orbit, resulting in the largest apparent size of the lunar disk as seen from Earth. 

The Moon's distance varies each month between approximately 357,000 kilometers (222,000 mi) and 406,000 km (252,000 mi) due to its elliptical orbit around the Earth (distances given are center-to-center).

The Supermoon of Nov 14, 2016

On November 14, 2016, the moon will be closer to Earth than it’s been since January 26, 1948. It’ll be a full moon and a supermoon. The moon won’t come this close again until November 25, 2034. That makes upcoming full moon the closest and largest supermoon in a period of 68 years!

Getting Technical on Supermoon

The term supermoon is relatively new. Before we called them supermoons, we in astronomy called them perigean full moons.

Moon is closest to Earth at perigee and farthest away at apogee. When the full moon aligns with perigee – as it does on November 14, 2016 – it’s a perigee full moon or supermoon. By the way, the moon’s orbit is much closer to being a circle than this diagram suggests.

Closest moon is nearly always a full moon?

Because of gravity, and the intriguing interplay of the sun, Earth and moon (and, to a lesser extent, the planets), the closest perigee of any given year is often the one that aligns most closely with full moon.

For the moon to appear full, the sun, Earth and moon need to be aligned, with Earth in the middle. During that particular alignment, the tidal pull of the sun and moon combine to create wide-ranging spring tides. And full moons at perigee create even wider-ranging perigean spring tides.

The diagram below helps to explain why the perigee full moon comes especially close to Earth. Take a careful look. Explanation below.

 

On the diagram above, the line connecting lunar perigee with lunar apogee defines the moon’s major axis (the longest axis of an ellipse).

When the moon’s major axis (apogee-perigee line) points sunward (A & C on the diagram), the eccentricity (flatness) of the moon’s orbit is increased to a maximum. A greater eccentricity lessens the perigee distance, while increasing the apogee distance.

At A in the diagram, it’s a perigee new moon (supermoon) and an apogee full moon (micro-moon).

Then 3.5 lunar months (some 103 days) later, at B in the diagram, the major axis is at a right angle to the sun-Earth line, so the eccentricity is minimal. At such times, the moon’s orbit is closest to circular. It’s a more distant perigee and closer apogee, with the first quarter and last quarter moons more or less aligning with apogee and perigee.

Then 7 lunar months (206 days) later, the major axis again points sunward. Once again, the eccentricity of the moon’s orbit is increased to a maximum, lessening the perigee distance yet increasing the apogee distance. This time around, it’s a full moon perigee and new moon apogee. See C in the diagram.

And don't miss it.

 

Fall Equinox - The beginning of Autumn

Often during Astronomy related conversations I used to hear word equinox and then they used to say Fall equinox and the spring equinox. The word seems weird but it has the explanation in it. Equinox is derived from Latin word aequus (equal) and nox (night), because around the equinox the day and night are of almost equal lengths.

Equinox is on September 22 and March 20, so who cares

An equinox occurs twice a year (around 20 March and 22 September), when the plane of the Earth's equator passes the center of the Sun. At this time the tilt of the Earth's axis is inclined neither away from nor towards the Sun. So what is so important about Equinox.

In very simple terms, let me tell you what is the equinox from observation point of view

Equinox: The Sun from Solstice to Solstice Credit & Copyright: Tunç Tezel (TWAN)

It shows how the path of the Sun varies across the sky between Summer Solstice (top path), Fall Equinox (middle path) and Winter Solstice (bottom path).
As you can clearly see, the Sun is the highest in the sky during summer and lowest in the winter, lying in between at the fall equinox.

Once again, someone might ask you what so important about Equinox. What will we see in the sky? There is nothing to see in the sky in the equinox except the Sun and if you are near the equator, except to feel the heat, the blue sky and the dark nights :) Usually during equinox it is hot during days and cool during nights at some places. What else can one benefit from Equinox?

Significance of Equinox

1. Sun will rise at exact East and will set at exact west if you are near the equator. You might be wondering that the Sun always sets at exact west and rises at exact East, this is not the cast. The below photo will explain it well.

The Sun rises due east and sets due west on the equinoxes in March and September. At other times of year it comes up and goes down somewhat to the north or south. This illustration is drawn for mid-Northern latitudes. Sky & Telescope illustration.

2. In northern hemisphere, the September equinox marks the start of Autumn and March equinox marks the start of Spring. In southern hemisphere it is opposite.

3. If you were standing on the equator, the Sun would pass exactly overhead at midday.

So a very simple concept, yet an important one and easy to understand.

Sun Set captured on the Equinox

 

Sun set on Fall Equinox September 22. Photo by Author

 

 

Perseid meteor shower set to put on a great show in August 2013

Perseid meteor shower set to put on a great show in August

Perseids Meteor Shower Peaks on 11th -13th August 2013

The Perseid meteor shower is a major annual event for sky-watchers and 2013 looks to be a great show. The Perseid meteor shower is one of the best meteor showers of the year. Luckily, the Moon (the source of light at night in the sky), will be set before the midnight, that is before the peak time of shower of meteor shower. That means no Moon to disturb us. Known as the most fantastic and accessible meteor shower of the year, the Perseids are expected to fill the "predawn skies with hundreds of shooting stars" on the evenings of Aug. 11-13, according to NASA.

Snowy Range Perseid Meteor Shower Credit: David Kingham Photography – facebook page

Meteor Shower is like shower in a bathroom?

Some people might think it is a shower like we take a shower in the bathroom. Many jokes are floating these days on facebook etc. related to this. Meteor Shower is an astronomical phenomenon where streaks of light appear in the sky at specific time in specific months and the lights lasts a fraction of seconds. The shower occurs when Earth passes the dust trails of a comet that passed near the orbit of the Earth.

Are the shooting stars, really stars?

They are sometimes called shooting stars and many people actually take them as if real stars are shooting because they have been broken down from the sky. The shooting stars are not at all real stars but pebble-sized or less or sometime bigger particles of dust that burns when they enter Earth’s atmosphere. They burn due to friction and the gravitational pull of Earth, and when they burn they leave a streak of light that lasts for less than a second.

The origin of Perseid meteor shower – Comet Swift-Tuttle

These are not the only Meteor Shower that happens in a year, but there are other great showers that occur during the year. However, since the Earth passes that area every year in the same month and time where Comet left particles, a Meteor shower occurs every year.

The meteor shower occurs in July and August as the Earth's orbit takes us through the debris of the Swift-Tuttle comet. Earth's gravity pulls in some of the chunks of debris — small rocks comprised of iron-nickel, stone, other minerals or a combination of these — which turn into bright balls of hot gas when entering Earth's atmosphere. As darkness falls, the meteors appear to come from the constellation Perseus, hence the name; although later in the evening, the meteors originate higher in the sky than the constellation. (http://www.universetoday.com/103826/the-2013-perseid-meteor-shower-an-observers-guide/#ixzz2aw3isqO7)

 

The orbit of comet Swift-Tuttle and its intersection near the Earth’s orbit. (Created by the author using NASA/JPL ephemerides generator).

Where and how to look for Perseids?

Meteors can appear randomly in any part of the sky! But for meteor showers such as Perseids look near the constellation of Perseus.

If a meteor shower is in progress it usually helps to look about 45 degrees either side of the radiant and about 30 degrees up. Looking straight at the radiant means you will see meteors head on and with very short trails, looking to one side of the radiant gives a reasonable length of trails but is still close enough to catch the majority of meteors. Looking about 30 degrees up means you are looking through a larger volume of air than when looking overhead, which should catch more meteors, but is still high enough to be above the haze.

Use Sky Charts and Planetarium software

As mentioned that the radiant (from where they seem to appear) is the constellation of Perseus. Now how to find Perseus might be difficult for beginners or some people who are new to Astronomy. For finding constellations, we use Sky Charts or Sky maps or a computer software such as Stellarium. These methods can help you find the constellation and then you can start with your observation. I would prefer to use Stellarium. Install it take your laptop on the observation site and once find the location and try to remember the constellation outline, or shape and then you can close the laptop so you avoid light and distraction.

Point towards North and look for Perseus

Let’s take an example to help you more. Below is the sky chart of the North east side of the sky. The names written are the names of constellations (areas in sky that are made by collection of stars to easily identify places in the night sky. Think of them as Continents on the world map). The Radiant word in yellow color appears to be in the continent of Perseus. That means they seem to come from that constellation. So don’t look directly in that constellation but as described above in first paragraph of this section.

 

 

Don’t worry if you cannot find the Perseus constellation, look directly towards North and move your head upwards to see for the “M” shaped constellation “Cassiopeia”. See below. And now you can find Perseus yourself. J

 

Meteor Shower Calendar2013


If you have a smart phone especially Android, then you can download an application named “Meteor shower Calendar” for free and you can have the above chart right in your smart phone always with you. So now you have both the tools, a smart phone application to find the constellations and an application to find the meteor shower dates and a reminder.

 

Can we see fireballs?

A few bigger particles survive to within 12 miles (20km) of the surface. These typically produce “fireballs” that glow as bright as or brighter than Venus. And yes we can see them if we are lucky. They last more or sometimes less than a second but they are rare.

 

Observing Perseids Meteor Shower

The key to watching meteors; is to be comfortable and keep your gaze on the sky!

The above scene seems quite a peaceful and comfortable way to watch the meteor shower.

Find a place where you can see most of the sky and you should be away from city lights. You should stay in darkness for a prolonged period of time to get dark adaption and then should avoid lights.

The key is to be comfortable while watching. Dress warmly as it could be cold and even if not it, you will feel cold. Lie on the ground or a rocking chair with a blanket or something to cover you.

Try to keep your gaze on the sky as many people tend to miss a few amazing meteors that everyone else observing there see it. You might see airplanes and some artificial satellites.

Can we observe the Showers from Pakistan?

Pakistan lies in the Northern hemisphere and the Perseids meteor shower is visible in the Northern hemisphere. The best way to watch is to watch on 11th, 12th and 13th August after mid-might starting around 2pm till dawn from a dark location having clear and transparent skies.

“I observed a Meteor Shower Geminds Shower back in Dec 2010 from Pakistan and counted over 150+ meteors overnight.” –Abubaker Siddiq, Organizing Head of KaAS

A detailed log of that event can be found here:

Geminids Watch 2010 at Kalri Lake

Happy Meteor Watching!

Watching meteor shower requires patience, keen eye, dark adoption and clear sky and you will be rewarded with an experience that you will not forget that easily like I haven’t forgot the Geminds meteor watching 2 and a half years back. This year in Pakistan and nearby areas, we have clouds these days and in the upcoming week too during the peak, but never lose hope as the sky can get really clear and transparent. Who knows? Happy Star Gazing!

I will update this article hopefully after the Meteor Shower if I catch some showers, so stay tuned. 

References

http://www.meteorwatch.org/science-observing/how-to-observe-meteors/

http://www.kpopstarz.com/articles/36647/20130803/perseid-meteor-shower-2013.htm

http://www.custerobservatory.org/meteors.htm

http://www.meteorwatch.org/meteor-info/meteor-showers-2013/

 


About the Author

The author Abubaker Siddiq Shekhani is a 26-year old amateur Astronomer obsessed by Moon since childhood. He is a Software Engineer by profession and loves to do adventures, travelling, observing nature and loves nature.