The sun is the source of over 99.9% of the energy arriving at the surface of the Earth and it is a very active place with giant solar flares and complex weather. This weather can hurl giant lumps of plasma called coronal mass ejections out into the solar system, knocking out power systems and satellites over 80 million miles away on Earth. Plus, we are just starting to understand the ways solar weather can affect the weather on earth.
On Thursday, NASA launced a new satellite called the Solar Dynamics Observatory designed to view the sun continuously at higher resolution, and at a higher rate than ever before, take a spectrum of the sun more than every 10 seconds and measure the magnetic field on the surface of the sun continuously.
This is going to produce a huge amount of data - about 1.5 terrabytes every day which needs a network connection of over 150Mbit/second. This means it has to be in a geostationary orbit over its basestation in America so it can keep transmitting all the time.
Hopefully it will let us get a much better understanding of the sun and its affects on the Earth.