Interface Region Imaging Spectrograph (IRIS) fills a crucial gap in our ability to advance Sun-Earth connection studies by tracing the flow of energy and plasma into the corona and heliosphere for which no suitable observations exist. IRIS obtains high, resolution UV spectra and images of the sun’s chromosphere, specifically on the non-thermal energy that creates the Corona and the Solar Wind; i.e., Space Weather.
IRIS is a Principal Investigator (PI) led Small Explorer Mission; PI is Alan Title located at Lockheed Martin Advanced Technology Center, Solar and Astrophysics Laboratory.
IRIS will obtain UV spectra and images with high resolution in space (1/3 arcsec) and time (1s) focused on the chromosphere and transition region of the Sun, a complex dynamic interface region between the photosphere and corona. In this region, all but a few percent of the non-radiative energy leaving the Sun is converted into heat and radiation. Here, magnetic field and plasma exert comparable forces, resulting in a complex, dynamic region whose understanding remains a challenge.
The IRIS science investigation is centered on three themes of broad significance to solar and plasma physics, space weather, and astrophysics, aiming to understand how internal convective flows power atmospheric activity:
- Which types of non-thermal energy dominate in the chromosphere and beyond?
- How does the chromosphere regulate mass and energy supply to corona and heliosphere?
- How do magnetic flux and matter rise through the lower atmosphere, and what role does flux emergence play in flares and mass ejections?
The complex processes and enormous contrasts of density, temperature and magnetic field within this interface region require instrument and modeling capabilities that are only now within reach. The IRIS team will use advances in instrumental and computational technology, its extensive experience, and its broad technological heritage to build a state-of-the-art instrument to provide unprecedented access to the plasma-physical processes in the interface region.
- IRIS advances our understanding of how the enigmatic interface region on the sun powers its dynamic million-degree atmosphere called the corona.
- IRIS contributes to our understanding of the energy flow that is deposited in the interface region, with only a fraction leaking through to drive solar wind that fills the heliosphere.
- IRIS improves our understanding of the interface region where most of the sun’s ultraviolet emission is generated that impacts the near-Earth space environment and Earth’s climate.
- The sun’s dynamically changing chromosphere and transition region make up the key “interface region” that IRIS will study that lies between the photosphere and corona.
- Beginning in 2013, the IRIS spacecraft will orbit Earth and use its ultraviolet telescope to obtain high resolution images and spectra of the interface region. IRIS observations will be taken every second and reveal details as small as 150 miles on the Sun.
- IRIS will use solar images and spectra and advanced computer models to deepen our understanding of how atmospheres on the Sun and other stars are energized.
- Earth continuously plows through the solar wind, a stream of charged particles emitted by the sun, and is affected by dramatic changes caused by extreme space weather events. IRIS increases our ability to forecast space weather, which can disable satellites, cause power grid failures, and disrupt GPS services.
- IRIS will join the Solar Dynamics Observatory (SDO) which launched in 2010 and Hinode (launched in 2006). Together they will explore how the solar atmosphere works and impacts Earth – SDO and Hinode monitoring the solar surface and outer atmosphere, with IRIS watching the region in between.
- IRIS is a NASA small explorer. The mission of the Explorers Program is to provide frequent flight opportunities for world-class scientific investigations from space within the heliophysics and astrophysics science areas.
Five questions your neighbor might ask
- What is Goddard’s role?
Mission management, science research
- How many people at Goddard are working on this?
GSFC has provided a mission management team (the primary Goddard management team is lead by Eric Ianson – Mission Manager, Joe Davila – Mission Scientist, Tim Trenkle – System Engineer, James Lohr – CSO and Valerie Makritis – MBM with the support of the NASA Explorer program at GSFC.)
Goddard has several scientists active with the mission.
- Why is this important to NASA and our nation?
The sun and space weather can pose a direct threat to our nation’s technology infrastructure and national security. The sun and space weather can pose a direct threat to all of NASA’s assets in space. The mission will enable a new and broader understanding of the Sun-Earth-Solar System connection and expand our fundamental understanding of the sun ,our personal star, connecting us to the rest of the universe.
- What’s the “cool” factor?
This mission provides us with a new “microscope” enabling scientists and the public to “see” into an incredibly dynamic yet poorly understood layer of our star. Goddard once again gets to play a key role in cutting edge engineering and technology, mission operations and science. This mission, like many NASA missions, opens up the door for other scientists, students, educators and the public around the world to explore a cutting edge view into our universe through mission data and outreach.
- Why should I care?
We are going to better understand a region of the sun that is a critical driver of solar activity and space weather. Understanding space weather much like understanding weather here on Earth allows us to better prepare and mitigate damage to our technological infrastructure. This ultimately helps improve our way of life and saves taxpayer money. This mission provides one more example of STEM in action and serves as a tool to better STEM education in our nation. Plus we are going to learn a lot about the universe around us through one of our best astrophysical laboratories, the sun.
The IRIS instrument is a multi-channel imaging spectrograph with a 20 cm UV telescope. IRIS will obtain spectra along a slit (1/3 arcsec wide), and slit-jaw images. The CCD detectors will have 1/6 arcsec pixels. IRIS will have an effective spatial resolution between 0.33 and 0.4 arcsec and a maximum field of view of 120 arcsec.
The far-UV channel covers: 1332-1358 Å and 1390-1406 Å
with 40 m Å resolution and an effective area of 2.8 cm2.
The near-UV channel covers: 2785-2835 Å
with 80 mÅ resolution and an effective area 0.3 cm2.
Slit-jaw imaging will have four passbands:
1335 Å and 1400 Å with 40 Å bandpass each
2796 Å and 2831 Å with 4 Å bandpass each
IRIS will have a high data rate (0.7 Mbit/s on average) so that the baseline cadence is: 5s for slit-jaw images, 1s for 6 spectral windows, including rapid rastering to map solar regions.
Launch, Deploy and Beauty Passes
IRIS Mission Trailer
IRIS Science Overview
IRIS Mission Video File