NASA is just about ready to embark on a new exploration mission bound for an unexplored region of the solar atmosphere. The purpose of the mission is to help astronomers learn more about an area located in the lower atmosphere of the sun, known as the interface region.
The Interface Region Imaging Spectrograph (IRIS) will launch in June from Vandenberg Air Force Base, Calif. Most of the sun's ultraviolet emissions come from the interface region and affect the Earth's climate and atmosphere.
The sun's atmosphere is made up of the photosphere, the chromospheres and the corona. The bubbling energy from the sun's inner layers pushes outward into these three layers becoming visible as sunlight.
The sun's energy is released as light through the photosphere which is about 300 miles thick and is the sun's lowest layer. Solar flares which produce ultraviolet radiation, x-rays, electromagnetic radiation and radio waves come from the photosphere.
The chromosphere is the next layer where high temperature hydrogen burns off, appearing to have a red glow which is only visible during a total solar eclipse.
The final layer of the sun's atmosphere is the corona which is also only visible during a total solar eclipse, appearing as plumes of ionized gas flowing outward. In the sun's corona, temperatures can reach up to 3.5 million degrees Fahrenheit and becomes solar wind as the gases cool.
The region IRIS is set to explore is located between the sun's surface which has a reported temperature of 11,000 degrees Fahrenheit, the photosphere and the upper corona. High resolution photos of the sun and spectra will be taken by IRIS as it orbits the Earth packing an ultraviolet telescope.
"Understanding the interface between the photosphere and corona remains a fundamental challenge in solar and heliospheric science," reads NASA's mission statement.
Observation data collected from IRIS and 3-D computer models will help broaden the understanding of how heat and energy is transferred through the sun's corona.
