A solar flare is a large ejection of plasma from the Sun. The solar flare can be ejected towards or away from the Earth. They are not a new phenomena, they've been happening for years and millenias, it is only as we look to the Sun and study it that we now see and notice these solar flares. You should never look at the Sun to see if you can see a flare because your eyes will become damaged long before you see one. The flare will probably not have happened by the time your eyes will have gone bad. To look for a solar flare, you'd need special telescopes. The below picture taken by NASA is of a Corona Mass Ejection (CME) and how big they are compared to the Earth. The corona will eventually break free from the Sun and head off into space. where it may or may not come into contact with the Earth. For the record, the Earth is not that close to the Sun.
Fortunately, we have a magnetic force field, the picture courtesy of NASA that surrounds and protects us from harmful solar rays. If we didn't have a magnetic field, our atmosphere would have been stripped away long ago. It is said that life never started on Mars because it didn't have a magnetic field to protect it from the solar rays. In Knowing starring Nicholas Cage, the Earth is hit by a Solar Flare which destroys life on the planet. There is a theory that on Mars long ago, the atmosphere was destroyed by a solar flare. 5
Even though we have a magnetic field, we are not immune from solar flares. The Aurora Australis and Aurora Borealis are light shows in the Southern and Northern hemispheres respectively where the Sun's particles have hit our atmosphere and produce a light show. It is not just NASA and other space agencies that study the Sun but also energy and communication company. Communication companies will want to know when a Solar Flare will hit so that they can manoeuvre their satellite out of the the harmful plasma field. Energy companies on Earth will need to prepare themselves from energy spikes and damage to their electricity pylons.
On August 28th, 1859, Earth experienced the largest solar storm to have ever hit the planet. Back in those days, electricity was only in its infancy and there was definitely no mobile phone communications so there was no real damage caused. A solar flare on that size has been estimated to be able to cost somewhere in the region of 0.6 - 2 Trillion dollars1. The Sun goes through a cycle of 11 years of activity when it can appear more active and then more docile than at previous years.
In modern times, there have been two notable incidents of solar flares affecting the power grid, they are Quebec storm of March 1989 which caused a hydroelectric dam to shut down and cause the loss of power to an estimate six million people for nine hours, causing a financial loss of $13.2 Billion. The second was the Halloween 2003 incident, there was a power shortage caused by a solar flare. When a solar flare is launched, the astronauts in the International Space Station have to move to a safe location within their shuttle, failure to do so can be fatal for them.
The below is a NASA video of a solar flare which they' ve put on Youtube to share.
The Auroras are better known by their English names as the Northern and Southern Lights. The simplest explanation of what causes the Auroras is charged particles hitting the atmosphere giving off a light show. Most Auroras occurs in the very north or very south but they have been known (Borealis) to be seen as far south as the Channel Islands near France.2 . Whilst most associate the colours of the Auroras as being green, they can appear as different colours. The colour of the lights is dependent on the gas that the northern lights hit and at what altitude the collision between the particles and the gasses hit.3
Auroras are not just limited to the Earth, any planet that has a magnetosphere will be able to experience an aurora show.
The reason why only the polar caps of the north and south poles and not the equator get auroras is because of the flow of the magnet field that protects the planet. At the heart of the Earth is a molten iron core which generates the magnet field that protects us. When particles from the Sun hit our planet, they are pushed to the top of the magnetosphere as you can see from the picture above, the magnet fields only reach the polar regions therefore the interaction between the particle required for an aurora can only occur there. It is impossible for an aurora to appear in the Equator but is extremely rare.4. The below video is something that I found on YouTube showing a time-lapsed video of an Aurora Borealis. For other pictures of auroras, visit Christopher Tandy Photography. If you looked at the northern lights, the lights would not move as fast as they do here, they'd be quite static.