For centuries, every civilization on Earth has looked skyward to the sun and depended on it for energy, heat, light and even a place of worship. Ancient sun worshippers believed the sun to be a deity and would offer sacrifices and tributes to the sun gods and goddesses. Today, scientists look to the sun for knowledge about our atmosphere and how it impacts life on Earth.
The sun is the nearest star to Earth. It provides energy to millions and has been studied more than any other part of our galaxy. Recent findings from a NASA satellite have provided more details about the sun's outer atmosphere than have ever previously been discovered.
The Interface Region Imaging Spectrograph (IRIS), launched by NASA in June 2013, is a small explorer satellite orbiting Earth with a telescope on board that is getting up close and personal with the part of the Sun's atmosphere known as the "chromosphere." It's this middle layer of the Sun's atmosphere, also called the "interface" region, which is providing researchers with some surprising information.
There are five findings that have most intrigued the team analyzing the data from IRIS. They are:
--Hot Pockets. No, not snack food, but something much more interesting. The satellite has discovered pockets of heat much lower in the region than any other spacecraft has found. These pockets are super heated to 200,000 degrees Fahrenheit and are referred to as "heat bombs" by scientists because they release such large amounts of energy in a very short time. Understanding these pockets will be key for understanding how the rest of the atmosphere is heated.
--Loops. The telescope on board the IRIS satellite has sent back images with incredibly high resolution and they reveal numerous loops of solar material. Evidence suggests that these loops are the structures that transfer energy between the solar regions. The images will provide researchers with a way to model coronal loops for further study.
--Tornadoes. The wizard can't help Dorothy get away from these twisters. Moving at 12 miles per second, scientists believe that the energy stirred up from these mini-tornadoes is transferred from the interface region to the corona, contributing to the super hot temperatures there.
--Breaking Wind. Scientists have long sought to understand more about how the solar wind works. The IRIS satellite has detected powerful jets that explode from coronal holes, where the atmosphere is less dense. These jets are much like fountains, only they shoot plasma in short bursts. Scientists believe these short jets are an ongoing source of the solar wind.
--Flares. While large solar flares in the corona have been studied and observed in previous missions, for the first time scientists have discovered small nanoflares that are impacting the interface region. Normal solar flares in the corona shoot energized particles into space at a high rate of speed, often affecting satellites and power grids. These much smaller nanoflares, in addition to contributing to coronal heating are creating high-energy particles that are showing up in the chromosphere.
While budgetary issues and cost factors are always a concern in satellite missions such as this, according to Bart DePontieu, IRIS project Science Lead, "This research really delivers on the promise of IRIS, which has been looking at a region of the sun with a level of detail that has never been done before."