NASA's IRIS provides unprecedented images of sun

December 09, 2013

The region located between the surface of the sun and its atmosphere has been revealed as a more violent place than previously understood, according to images and data from NASA's newest solar observatory, the Interface Region Imaging Spectrograph, or IRIS.

Solar observatories look at the sun in layers. By capturing light emitted by atoms of different temperatures, they can focus in on different heights above the sun's surface extending well out into the solar atmosphere, the corona. On June 27, 2013, IRIS, was launched, to study what's known as the interface region - a layer between the sun's surface and corona that previously was not well observed.

Over its first six moths, IRIS has thrilled scientists with detailed images of the interface region, finding even more turbulence and complexity than expected. IRIS scientists presented the mission's early observations at a press conference at the Fall American Geophysical Union meeting on Dec. 9, 2013.

"The quality of images and spectra we are receiving from IRIS is amazing," said Alan Title, IRIS principal investigator at Lockheed Martin in Palo Alto, Calif. "And we're getting this kind of quality from a smaller, less expensive mission, which took only 44 months to build."

For the first time, IRIS is making it possible to study the explosive phenomena in the interface region in sufficient detail to determine their role in heating the outer solar atmosphere. The mission's observations also open a new window into the dynamics of the low solar atmosphere that play a pivotal role in accelerating the solar wind and driving solar eruptive events.

Tracking the complex processes in the interface region requires instrument and modeling capabilities that are only now within our technological reach. IRIS captures both images and what's known as spectra, which display how much of any given wavelength of light is present. This, in turn, corresponds to how much material in the solar atmosphere is present at specific velocities, temperatures and densities. IRIS's success is due not only to its high spatial and temporal resolution, but also because of parallel development of advanced computer models. The combined images and spectra have provided new imagery of a region that was always known to be dynamic, but shows it to be even more violent and turbulent than imagined.

"We are seeing rich and unprecedented images of violent events in which gases are accelerated to very high velocities while being rapidly heated to hundreds of thousands of degrees," said Bart De Pontieu, the IRIS science lead at Lockheed Martin. "These types of observations present significant challenges to current theoretical models."

DePontieu has been culling images of two particular types of events on the sun that have long been interesting to scientists. One is known as a prominence, which are cool regions within the interface region that appear as giant loops of solar material rising up above the solar surface. When these prominences erupt they lead to solar storms that can reach Earth. IRIS shows highly dynamic and finely structured flows sweeping throughout the prominence.

The second type of event is called a spicule, which are giant fountains of gas - as wide as a state and as long as Earth - that zoom up from the sun's surface at 150,000 miles per hour. Spicules may play a role in distributing heat and energy up into the sun's atmosphere, the corona. IRIS imaging and spectral data allows us to see at high resolution, for the first time, how the spicules evolve. In both cases, observations are more complex than what existing theoretical models predicted.

"We see discrepancies between these observations and the models and that is great news for advancing knowledge," said Mats Carlsson, an astrophysicist at the University of Oslo in Norway. "By seeing something we don't understand we have a chance of learning something new."

Carlsson helps support the crucial computer model component of IRIS' observations. The computer models require an intense amount of power. Modeling just an hour of events on the sun can take several months of computer time. IRIS relies on supercomputers at NASA's Ames Research Center in Moffett Field, Calif., the Norwegian supercomputer collaboration and the Partnership for Advanced Computing in Europe.

Such computer models had helped design the IRIS instruments by providing a basis for the instrument performance requirements. Currently, they are used for analysis of IRIS data, as they represent the state of knowledge about what scientists understand about the interface region. By comparing models with actual observations, researchers figure out where the models fail, and therefore where the current state of knowledge is not complete.

By filling in these gaps, IRIS observations are helping round out our images of the solar atmosphere. The Japanese Aerospace Exploration Agency/NASA Hinode mission provides detailed imagery of the solar surface. NASA's Solar Dynamics Observatory offers imagery of what's higher up in the corona. Now, IRIS provides unprecedented information about the crucial layer in between, to finally help us understand how energy moves through the lower levels of the solar atmosphere driving the solar wind and heating the corona.

The IRIS Observatory was designed and the mission is managed by Lockheed Martin. The Harvard-Smithsonian Center for Astrophysics in Cambridge, Mass., built the telescope. Montana State University in Bozeman, Mont. designed the spectrograph. NASA Ames provides mission operations and ground data systems. NASA's Goddard Space Flight Center, in Greenbelt, Md. manages the Small Explorer Program for NASA's Science Mission Directorate in Washington, D.C. The Norwegian Space Centre is providing regular downlinks of science data. Other contributors include the University of Oslo and Stanford University in Stanford, Calif.
-end-
For more information about IRIS, visit:

http://www.nasa.gov/iris

NASA/Goddard Space Flight Center

Related Solar Wind Articles from Brightsurf:

Wind beneath their wings: Albatrosses fine-tuned to wind conditions
A new study of albatrosses has found that wind plays a bigger role in their decision to take flight than previously thought, and due to their differences in body size, males and females differ in their response to wind.

New research deepens understanding of Earth's interaction with the solar wind
A team of scientists at PPPL and Princeton University has reproduced a process that occurs in space to deepen understanding of what happens when the Earth encounters the solar wind.

Hydropower plants to support solar and wind energy in West Africa
Study maps smart electricity mix composed of solar, wind and hydropower for West Africa -- regional cooperation can provide up to 60% reliable and clean electricity

Solar and wind energy sites mapped globally for the first time
Researchers at the University of Southampton have mapped the global locations of major renewable energy sites, providing a valuable resource to help assess their potential environmental impact.

New research helps explain why the solar wind is hotter than expected
When the sun expels plasma, the solar wind cools as it expands through space -- but not as much as the laws of physics would predict.

Solar wind samples suggest new physics of massive solar ejections
A new study led by the University of Hawai'i (UH) at Mānoa has helped refine understanding of the amount of hydrogen, helium and other elements present in violent outbursts from the Sun, and other types of solar 'wind,' a stream of ionized atoms ejected from the Sun.

Supporting structures of wind turbines contribute to wind farm blockage effect
Much about the aerodynamic effects of larger wind farms remains poorly understood.

Parker Solar Probe traces solar wind to its source on sun's surface: coronal holes
New data from the Parker Solar Probe, which got closer to the sun than any other spacecraft, allowed physicists to map the source of a major component of the solar wind that continually peppers Earth.

Closest-ever approach to the sun gives new insights into the solar wind
The Parker Solar Probe spacecraft, which has flown closer to the sun than any mission before, has found new evidence of the origins of the solar wind.

SwRI-built instrument confirms solar wind slows farther away from the Sun
Measurements taken by the Solar Wind Around Pluto (SWAP) instrument aboard NASA's New Horizons spacecraft are providing important new insights from some of the farthest reaches of space ever explored.

Read More: Solar Wind News and Solar Wind Current Events
Brightsurf.com is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to Amazon.com.