NASA has launched its latest probe which will try to discover why the Sun is so hot.
The answer is not as obvious as you may think, because at one point the temperature actually drops as you move closer to the core.
Scientists hope it will shed light on solar changes that affect the weather and electronic communications on earth.
ITV News Reporter Martha Fairlie explains:
The Interface Region Imaging Spectrograph, or IRIS will show the lowest levels of the sun’s atmosphere, the interface region, in more detail than has even been observed before over the next two years.
This will help scientists understand how the energy moving through this area helps power the sun’s million-degree upper atmosphere, the corona, as well as how this energy powers the solar wind constantly streaming off the sun to fill the entire solar system.