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Saturday, 25 February 2017

451) Southern Lights (New Zealand): A Commemorative $1 holographic Silver Coin released by the Reserve Bank of New Zealand on 18.01.2017:

451) Southern Lights (New Zealand): A Commemorative $1 holographic Silver Coin released by the Reserve Bank of New Zealand on 18.01.2017:

The Reserve Bank of New Zealand (RBNZ) has issued a new silver coin which highlights the Southern Hemisphere’s own natural and astounding light show.

The Southern Lights:

The Southern Lights as they are called form a spell-binding natural light show that produces shimmering sheets of colourful light that appear to dance across the sky.

Most people are very familiar with the Northern Lights (the “Aurora Borealis”), which have fascinated and amazed those living in the Northern Hemisphere, whereas, the natural phenomenon occurs around both the Northern and Southern polar regions.

The term “Aurora” was coined by Galileo Galilei in 1619, named after the Roman goddess of Dawn and the Greek name for the North wind.

The Southern counterpart of the Northern Lights is called the “Aurora Australis” which has features almost identical to the “Aurora Borealis” and changes simultaneously with changes in the Northern Auroral Zone. It is visible from High Southern latitudes in Antarctica, Chile, Argentina, New Zealand and Australia.

Most Auroras – Northern and Southern – occur in a band known as the “Auroral Zone” which is typically 3 degrees to 6 degrees wide in Latitude and between 10 degrees to 20 degrees form the geo-magnetic poles at all local times. A Region which displays an Aurora id called the “Aurora Oval”.

What causes the Auroras?

The “Lights of Auroras”, as they are called occur when gaseous particles/atoms in the Earth’s atmosphere collide with charged particles released from the Sun’s atmosphere they cause electrons in the atoms to move to a higher-energy state. When the electrons drop back to a lower energy state, they release a photon – light. This process creates the Northern & Southern lights.

Solar winds blow charged particles called electrons and protons towards the Earth, where they are largely deflected by the Earth’s magnetic field.

 The reason these lights do not occur in the Equatorial Regions is that the flows of energetic electrons and protons that trigger auroras travel along the Earth’s magnetic field lines that connect the distant geomagnetic tail region with the Earth’s surface field. These field lines reach the Earth only in the polar caps areas. The magnetic field is weaker at both the poles, allowing some particles to enter the Earth’s atmosphere and collide with gas particles. Variations in colour are caused by the collisions of varying gas particles.

The Colours of the Auroras:

The Southern Lights can range in colour from red, green, yellow, blue, pink, green, purple, ultraviolet or infrared with the colours dependant on a number of factors. The type of solar wind particle, the type of gas molecule and the electrical state at the time of collision – all have an effect on the eventual colour of the Aurora.

Green auroras are the most common and are produced by oxygen molecules located about 60 miles above the earth. The rarer red auroras are produced by high-altitude oxygen, at heights of up to 200 miles.

Nitrogen gases are needed to produce blue or purple aurora lights. These collisions emit light that we perceive as the dancing lights of the auroras and if one sees them once, they a sight that one remembers for a lifetime.

Interestingly, an “Aurora noise”, similar to a hissing or crackling sound begins approx. 70 metres (or 230 feet) above the Earth’s surface and is caused by charged particles in an inversion layer of the atmosphere formed during a cold night. The charged particles discharge when particles from the sun hit the inversion layer creating the noise.

New Zealand is home to the world’s largest dark-sky reserve, making it the perfect location for star gazing and observing nature’s ultimate light show.

About the Coin:

The Reverse of the New Zealand $1 Silver coin recreates the “magic” of the Southern Lights in both colour and its shimmering surface.

On the upper periphery are inscribed “SOUTHERN LIGHTS” & “AURORA AUSTRALIS

This coin has been minted by using a holographic foiling technique which best recreates the mesmerising shimmering of the Southern Lights. In the foreground of the image is the picturesque Church of the Good Shepherd at Lake Tekapo, where the Aoraki Mackenzie International Dark Sky Reserve is located. 
 The Obverse of the New Zealand $1 Silver coin shows a portrait of Queen Elizabeth II which was designed by Ian Rank-Broadley (IRB) which has been used on all New Zealand circulation and several commemorative coins since 2000, (this portrait has since been replaced by a portrait designed by Jody Clark in British coinage in 2016). On the left periphery is inscribed the name of the issuing country “NEW ZEALAND” and on the right Periphery is mentioned “ELIZABETH II”.

The specifications of the coin are:

Denomination: $1; Metal Composition: .999 Silver; Weight: 31.1 grams; Diameter: 40.0 mm; Coin Quality: Proof & Holographic foil; Mintage Limit: 1,500 pieces.

Non-terrestrial Auroras:

Both Jupiter and Saturn have magnetic fields stronger than that of the Earth and auroras have been observed on both the “gas planets” through the Hubble Space Telescope (HST), as well as on Venus, Mars, Uranus and Neptune.

Jupiter’s moons, in particular Io, are powerful sources of Auroras on Jupiter.
 An Aurora seen on Jupiter. On the far left there is a bright spot which connects magnetically to Io. The spots at the bottom of the image lead to Ganymede and Europa
 An Aurora high above the Northern part of Saturn taken by a moving spacecraft

Links to Posts on Australia, New Zealand and countries and Overseas Territories of the South Pacific on this blog:

1) Bank of Papua New Guinea: 36th Anniversary Celebrations (1973-2008): A Commemorative Uncirulated Coin Set consisting of a 2 Kina Banknote & a 2 Kina Coin

2) Papua New Guinea: An uncirculated coin set brought out in 1995 commemorating the 20th Anniversary of Independence 

 3) Currency & Coinage of the Soloman Islands: Dollars and Cents

4) New Zealand: New Banknote "Seventh Series" issued under Project "Brighter Money" from 2015 onwards

5) Coinage of the French Polynesian Island of Caledonia (or Nouvelle Caledonie) the CFP Franc  

6) French Institution for issuing uniform currency/coinage for French Overseas Territories in the Pacific and the French Southern Territories of Antarctica: The Institut d'emmission d'outre Mer (IEOM)

7) Currency & Coinage of Samoa: Tala and Sene 

8) Currency of the South Pacific Island Country of Fiji 

9) Coinage of New Zealand: A commemorative coin set issued in 1979 

10) Currency and Coinage of Australia: Dollars and Cents 

11) The Australian Emblem or the Coat of Arms 

12) The story of the Australian Penny 

13) The Legend of the Mutiny on the Bounty: A Commemorative Coin Set from the Pitcairn Islands depicting relics from the Bounty issued in 2009 

14) An Australian $5 coin issued in 1996, commemorating Australia's greatest cricketing legend - Sir Donald Bradman 

15) New Series/Generation of Australian Banknotes being introduced from 01.09.2016 onwards starting from $5 issues 

16) Southern Lights: A $1 Silver holographic coin issued by the Reserve Bank of New Zealand in January 2017

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