NASA Telescope Captures Sharpest Images of Sun's Corona

Dwayne Brown

Headquarters, Washington

202-358-1726

dwayne.c.brown@nasa.gov

 

Janet L. Anderson

Marshall Space Flight Center, Huntsville, Ala.

256-544-0034

janet.l.anderson@nasa.gov

WASHINGTON -- A telescope launched July 11 aboard a NASA sounding rocket has captured the highest-resolution images ever taken of the sun's million-degree atmosphere called the corona. The clarity of the images can help scientists better understand the behavior of the solar atmosphere and its impacts on Earth's space environment.

"These revolutionary images of the sun demonstrate the key aspects of NASA's sounding rocket program, namely the training of the next generation of principal investigators, the development of new space technologies, and scientific advancements," said Barbara Giles, director for NASA's Heliophysics Division at NASA Headquarters in Washington.

Launched from White Sands Missile Range in New Mexico, the 58-foot-tall sounding rocket carried NASA's High Resolution Coronal Imager (Hi-C) telescope. Weighing 464 pounds, the 10-foot-long payload took 165 images during its brief 620-second flight. The telescope focused on a large active region on the sun with some images revealing the dynamic structure of the solar atmosphere in fine detail. These images were taken in the extreme ultraviolet wavelength. This higher energy wavelength of light is optimal for viewing the hot solar corona.

"We have an exceptional instrument and launched at the right time," said Jonathan Cirtain, senior heliophysicist at NASA's Marshall Space Flight Center in Huntsville, Ala. "Because of the intense solar activity we're seeing right now, we were able to clearly focus on a sizeable, active sunspot and achieve our imaging goals."

The telescope acquired data at a rate of roughly one image every 5 seconds. Its resolution is approximately five times more detailed than the Atmospheric Imaging Assembly (AIA) instrument flying aboard NASA's Solar Dynamics Observatory (SDO). For comparison, AIA can see structures on the sun's surface with the clarity of approximately 675 miles and observes the sun in 10 wavelengths of light. Hi-C can resolve features down to roughly 135 miles, but observed the sun in just one wavelength of light.

The high-resolution images were made possible because of a set of innovations on Hi-C's optics array. Hi-C's mirrors are approximately 9 1/2 inches across, roughly the same size as the SDO instrument's. The telescope includes some of the finest mirrors ever made for space-based instrumentation. The increase in resolution of the images captured by Hi-C is similar to making the transition in television viewing from a cathode ray tube TV to high definition TV.

Initially developed at Marshall, the final mirror configuration was completed with inputs from partners at the Smithsonian Astrophysical Observatory (SAO) in Cambridge, Mass., and a new manufacturing technique developed in coordination with L-3Com/Tinsley Laboratories of Richmond, Calif.

The high-quality optics were aligned to determine the spacing between the optics and the tilt of the mirror with extreme accuracy. Scientists and engineers from Marshall, SAO, and the University of Alabama in Huntsville worked to complete alignment of the mirrors, maintaining optic spacing to within a few ten-thousandths of an inch.

NASA's suborbital sounding rockets provide low-cost means to conduct space science and studies of Earth's upper atmosphere. In addition, they have proven to be a valuable test bed for new technologies for future satellites or probes to other planets.

Launched in February 2010, SDO is an advanced spacecraft studying the sun and its dynamic behavior. The spacecraft provides images with clarity 10 times better than high definition television and provides more comprehensive science data faster than any solar observing spacecraft in history.

Partners associated with the development of the Hi-C telescope also include Lockheed Martin's Solar Astrophysical Laboratory in Palo Alto, Calif.; the University of Central Lancashire in Lancashire, England; and the Lebedev Physical Institute of the Russian Academy of Sciences in Moscow.

For more information about SDO, visit http://www.nasa.gov/sdo.

For more information about NASA's sounding rocket program, visit http://sites.wff.nasa.gov/code810/.

For more information about Hi-C, visit http://www.nasa.gov/topics/solarsystem/features/hic.html.

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Independence Day Solar Fireworks

This image, captured by the Solar Dynamics Observatory, shows the M5.3 class solar flare that peaked on July 4, 2012, at 5:55 AM EDT. The flare is shown in the 131 Angstrom wavelength, a wavelength that is particularly good for capturing the radiation emitted from flares. The wavelength is typically colorized in teal as shown here.

Image Credit: NASA/SDO/AIA/Helioviewer

Sunrise To Sunset: Observatory Looks To The Sky

The sun.

While it supplies life and energy for the people and plants that call the Earth home, also has the power to seriously disrupt humanity’s way of life.

Periodically, the sun releases massive quantities of solar matter and electromagnetic radiation into space, known as a coronal mass ejection, which can cause a geomagnetic storm that could potentially disrupt radio transmissions, damage satellites, and lead to long-lasting power outages.

To help Holloman AFB combat negative effects CMEs could have on the base’s mission, the solar analysts of the Detachment 4, 2nd Weather Squadron Solar Observatory here monitor the sun and its activities daily.

“We analyze the sun for features that may affect communications systems, satellites, and aircraft that are flying in higher elevations,” said Senior Airman Erin O’Connell, Det. 4, 2nd WS solar analyst. “Right now, the sun is very active and has been since early last year.”

The sun is active, O’Connell said, because we are currently in the solar maximum or solar max, which is the period of greatest solar activity in the sun’s solar cycle. During the solar max, large numbers of sunspots appear because the sun’s magnetic field lines are the most distorted due to the magnetic field on the solar equator rotating at a slightly faster pace than at the solar poles.

“If you imagine a bell curve, we are ramping up to a solar max right now, so we’re seeing a lot of flares and not only are they increasing in frequency, but the intensity of the flares are also increasing,” said Master Sgt. Shane Siebert, Det. 4, 2nd WS detachment chief. “The solar max and solar min, or solar minimum, cycles through every 11 years. Our solar min was in 2010, so just to put it in perspective, from 2010 to 2011 we saw a 300 percent increase in solar activity. We can expect the sun to stay active for the next three years, and then slowly decline for the next eight leading back to the solar min.”

Because solar activity can cause navigation systems anomalies, targeting systems errors, and disrupt the base’s communication assets, the solar analysts monitor the sun from sunrise to sunset.

“We have a very complex telescope that views the sun and feeds information to all of our computer systems, which enables us to analyze the sun and look for the features that are important to military and civilian customers that are impacted by space,” Siebert said. “As soon as we see those features, we compose a warning and send it to the Space Weather Prediction Center and the Space Weather Operations Center, and they disseminate the information to the decision makers and customers.”

Because the effects of a solar flare can be felt on Earth in eight minutes, the solar analysts must send the warning out in two minutes.

“The telescope puts live images on the screen, and when an event-level flare (flare that is very intense and very large, that emits high energy particles into space) happens, the system sounds an alarm and that’s when the two-minute warning comes into effect,” O’Connell said. “The telescope images the sun in the light of Hydrogen-alpha. This wavelength allows us to really see the solar activity, basically as its happening. We also can image the sun in white light, which shows sunspots on the sun’s surface or photosphere.”

Even when they’re not responding to event-level solar flares, the analysts still must monitor the sun’s activity very closely.

“Over the course of the day, we issue messages to the space community every three hours to let them know what kind of activity is occurring on the sun,” Siebert said. “In addition to this, the solar analysts also perform a sun spot drawing every day and forward that information to the Space Weather Prediction Center, so the forecasters can predict the likelihood of large flares.”

Even in their own Air Force Specialty Code, the solar analysts have a very unique mission, Siebert said.

“We’re all weather forecasters and in our career field there are 3,000 enlisted people, but in the solar community doing this job here, there are only 25 of us,” he said. “This is a very unique mission because there are only five different Air Force sites across the world doing this mission. They’re set up geographically in Australia, Italy, Massachusetts, Hawaii, and here, and there are usually always two observatories monitoring the sun at any given time.”

With event-level flares occurring daily, the solar analysts’ margin of error is ever decreasing.

“If we fail our two-minute warning, we set everyone else back,” Siebert said. “A lot is riding on us to do the job correctly – $104 billion in DoD assets can be damaged. During the true solar max, which we’re ramping into, the events could be happening several times an hour, so we’ll get even lot busier.”

Even with the increase in work load, Siebert is confident in the analysts’ abilities.

“When I first got here, there wasn’t a whole lot of activity going on,” Siebert said. “There would be days when there weren’t any flares. Now, we could face 20 flares a day, but we’re ready to respond and provide that information so that the customers at Holloman and throughout the DoD can be aware of when there’s going to be operational impacts to their missions.”

By Airman 1st Class Siuta B. Ika

49th Wing Public Affairs

One Ring to Bring Them All: Eclipse Enchants Grand Canyon Audiences

Ever see ringlets of sunlight playing in the shadows of a tree or a fiery ring of light in the sky? These incredible effects are the results of an annular solar eclipse like the one that occurred when the moon passed directly between the sun and Earth on Sunday, May 20, 2012. The event was viewable from Japan all the way across the Pacific Ocean to midway through the United States.

Because the moon travels on a slightly tilted orbit compared to the plane of Earth’s orbit around the sun, eclipses do not occur every time the moon comes between the sun and Earth. However, there are two points or "nodes" when the moon does pass through this plane. If either of these nodes coincides with a new moon (when the sun is illuminating only its far side), a solar eclipse will occur. If a node is reached during a full moon, Earth will block the sun’s light, casting a shadow onto the moon causing a lunar eclipse.

An annular eclipse occurs when the moon is too far away from us to completely cover the disk of the sun. This results in an annularity: the ring-shaped outline of the sun that can be seen surrounding the dark new moon. Because of the surreal look of the "ring of fire," annular eclipses are some of the most impressive celestial events visible from Earth.

This eclipse passed over some of the U.S.’s most famous national parks with the full annularity visible from 33 parks, while an additional 125 parks witnessed a partial eclipse. The NASA Lunar Science Institute (NLSI) at NASA’s Ames Research Center, Moffett Field, Calif., and the National Parks Service took advantage of this rare event and joined forces to facilitate safe viewings for as many people as possible.

Several NLSI scientists traveled to the Grand Canyon National Park and used the superimposition of our two most prominent celestial objects as an opportunity to explain to several thousand visitors about some of NASA's past, current and future projects relating to the sun and moon. These include the Lunar Atmosphere and Dust Environment Explorer (LADEE), which will orbit the moon in order to characterize its atmosphere and the lunar dust environment, and the Interface Region Imaging Spectrograph, (IRIS) which will make detailed measurements of the flow of energy and plasma through the sun's atmosphere and heliosphere.

The NLSI team gave presentations to three full-house audiences in the park’s theater and hosted an exhibit in its main visitor center. Samples of moon and Mars rocks and meteorites that people could handle were on display, as well as a model of a LADEE.

"Multiple missions to the moon in the past five years have revealed our nearest celestial neighbor is a fascinating place," said NLSI director Yvonne Pendleton, who spoke at the event. "The Apollo-era views, rich in geological insights from samples that continue to be studied today, have been enlarged to reveal detailed topography, composition and a bombardment history that will fascinate researchers for many years to come."

More than 2,000 people viewed the eclipse at the event. Safe viewing equipment was also sent to other national parks and another public viewing was held by one of the NLSI teams at the University of Colorado football stadium in Boulder, where 10,000 people viewed the partial eclipse.

"Nature has provided us with a unique opportunity to capitalize on the huge public interest in the sun and moon," said NLSI Director of Education and Public Outreach Brian Day. "It is an excellent opportunity to engage with the public and explain what we are doing at Ames."

Although there have been a number of partial eclipses in recent years, May 20, 2012 was the first time in 18 years that we have been able to see the moon pass directly across the center of the sun from the U.S.

James Schalkwyk

Ames Research Center, Moffett Field, Calif.

Solar Adaptive Optics

Steve Hegwer, technical support manager of the Dunn Solar Telescope at the National Science Foundation's (NSF) National Solar Observatory (NSO) in Sunspot, N.M., inserts a white card into the light path of the Dunn's high-order adaptive optics system to check part of its operation. The system compensates for most of atmospheric blurring and allows the telescope to observe up to seven times sharper than before (0".14, corrected, compared to 1".0, uncorrected). Success with this project has paved the way for NSO to design and propose the NSF-funded four-meter Advanced Technology Solar Telescope, the world's largest optical solar telescope.

(Date of Image: unknown)

Credit: Dave Dooling, NSO/AURA/NSF