The Northern Lights have been occurring for thousands of years ”“ long before anybody had a scientific explanation for them. Many primitive people regarded the lights as an omen of war or misfortune; some Eskimo groups believed the lights were the spirits of children who had died at birth, or animal spirits dancing. The Algonquin Indians even believed that the lights were reflections of huge fires, constructed by the creator of the earth, Nanahbozho. In medieval Europe, the lights were said to foretell of famine, war or other disaster.

The lights are actually caused by the earth’s magnetic field interacting with solar winds, creating a type of light known as an aurora. As well as emitting heat and light, the sun also emits gas, sometimes known as solar wind. Upon reaching the earth, this gas will collide with the earth’s magnetic field and create energy. The excess energy created by these collisions is given off in the form of light emissions ”“ what we call the northern lights.

One of the fascinating things about seeing the northern lights is that the patterns and colors are constantly changing ”“ no two nights are exactly the same. The most common color is green, although just about any color ”“ red, blue, yellow or purple – can occur in more intense light displays, making the experience even more dramatic. The green color is created by oxygen molecules that are found about 60 miles above the earth; different types of gas particles help to create the other colors. Many people claim that the lights resemble a spectacular sunset or sunrise.

The lights actually occur during the day as well, although it’s virtually impossible to see them. The northern lights do occur year round, but the best time of year to observer them is during the equinoxes ”“ March/April and September/October. They also follow a cycle of about 11 years and scientists have determined they will be at their peak in 2013. At night, the best view of the lights is enjoyed with a clear sky, and no street lighting or other bright lights nearby. In general, if the sky is clear enough to see the Milky Way, your chances of seeing the northern lights are good.

The northern lights occur most frequently in the areas around both the North and South Poles, due to the strong magnetic fields found here. For this reason, the further north you travel, the better your chances of seeing the lights, although they have been seen as far south as Texas and Georgia. In Europe, Iceland and Scandinavia are ideal places to see them; and in North America, the best view is from Alaska and parts of Northern Canada. There are actually southern lights as well ”“ known as aurora australis ”“ although they can only be seen from parts of  Australia, Antarctica and South America.

The Cassini project was set up and executed by three agencies these being the National Aeronautics and Space Administration (NASA), the European Space Agency and the Italian Space Agency. The spacecraft was launched in 1997 with its mission being to explore the planet Saturn and its system. The spacecraft took 7 years to reach Saturn and once there its initial mission to explore the planet took a further 4 years to complete. However this raised many further questions about Saturn and with the spacecraft remaining healthy it is now into overtime in its mission. It is currently being used to try and answer some of the questions raised during its 4 year mission

The spacecraft made a pass over the northern polar region of Saturn in October 2009 and infrared instruments detected a stunning light display. The aurora is the largest identified in our solar system to date and towers a massive 1,200 kilometers above the northern hemisphere of the planet. Although scientists have long suspected the aurora was present, the images sent back by Cassini in November are the first time they have actually been viewed in high resolution and provided conclusive evidence of their existence.

Auroras generally form in the high latitudes around a planet’s magnet poles. They are known to occur on Earth, Saturn and Jupiter and are caused by charged particles plunging into a planet’s atmosphere along magnetic lines. This causes the atmosphere to glow and produces the stunning light shows typical of the aurora borealis on Earth.

The video images of the huge aurora above Saturn should help scientists better understand the processes involved in generating them. The moving images was put together from around 500 still pictures which were taken over an 81 hour period between the 5^th and 8^th of October 2009. The finished video showed that there are very rapid changes in the shape and brightness of the aurora as it gyrates above the planet. The height of the aurora should also provide some clues into the amount of energy that is required to light it up.

The Cassini mission is currently scheduled to continue until September 2010 and it will continue to send back data regarding Saturn and its surrounding system until this time. With 2009 drawing to a close the highlights of the year for the project have included multiple flybys of Titan and Enceladus. These are two of Saturn’s many moons and further flybys of these are planned for the remainder of the mission. Data ring scientists also paid close attention in August when Saturn went through the Solar Equinox with the sun crossing from the southern to the northern hemisphere and this provided excellent conditions to view the rings.

In the 12 years since its launch the Cassini spacecraft has proved to be a stunning success and the data and images it has sent back about the planet Saturn and its moons has greatly increased our understanding of the system. Hopefully further discoveries will be made in the coming weeks and months until the completion of the mission and that these will help scientists in their quest to understand our solar system.