NASA Releases First 3-D Images of the Sun

GREENBELT, Maryland, April 24, 2007 (ENS) - Two NASA spacecraft orbiting the Sun together have recorded the first three dimensional images of the Sun and beamed them back to Earth. For the first time, scientists will be able to see structures in the Sun's atmosphere in three dimensions, helping them to better predict space weather that could disrupt Earth's satellites and power grids.

NASA's twin Solar Terrestrial Relations Observatory, STEREO, spacecraft were launched together October 25, 2006 from Cape Canaveral, Florida.

On January 21 they completed a series of complex maneuvers, including flying by the Moon, to position the spacecraft in two separate orbits about the Sun.

Fitted with suites of telescopes, they are now orbiting the Sun, one slightly ahead of Earth and one slightly behind.

Just as the slight offset between a person’s eyes provides depth perception, the separation of these spacecraft allows NASA to create 3-D images of the Sun.

The new view will help scientists to understand solar physics and improve space weather forecasting.


One of the first 3-D images of the Sun. This is not a true color image. To see the Sun in 3-D as STEREO sees it, special 3-D glasses are needed. (Photo courtesy NASA)
"In the solar atmosphere, there are no clues to help us judge distance. Everything appears flat in the 2-D plane of the sky. Having a stereo perspective just makes it so much easier," said Dr. Russell Howard of the Naval Research Laboratory, Washington. Howard is the principal investigator for the suite of telescopes on the spacecraft known as the Sun Earth Connection Coronal and Heliospheric Investigation project.

"With STEREO's 3-D imagery, we'll be able to discern where matter and energy flows in the solar atmosphere much more precisely than with the 2-D views available before," said Howard. "This will really help us understand the complex physics going on."

Violent solar weather originates in the Sun's atmosphere, or corona, and can disrupt satellites, radio communication, power grids and the Global Positioning System on Earth.

The corona resembles wispy smoke plumes, which flow outward along the Sun's tangled magnetic fields, making it difficult for scientists on Earth to tell which structures are in front and which are behind.

Of particular concern is a destructive type of solar eruption called a coronal mass ejection, CME. CMEs are eruptions of electrically charged gas, called plasma, from the Sun's atmosphere. NASA says a CME cloud can contain billions of tons of plasma and move at a million miles per hour.

A close up of loops in a magnetic active region of the Sun. These loops, observed by STEREO's telescope, are at a million degrees Celsius. This powerful active region, AR903, observed here on December 4, 2006, produced a series of intense flares over the next few days. (Photo courtesy NASA)
CME clouds are laced with magnetic fields and can smash into Earth’s magnetic field, causing magnetic storms that can overload power line equipment and radiation storms that disrupt satellites.

Satellite and utility operators can take precautions to minimize CME damage, but they need an accurate forecast of when the CME will arrive. To do this, forecasters need to know the location of the front of the CME cloud.

Data from the STEREO spacecraft will allow scientists to accurately locate the CME cloud fronts.

"Knowing where the front of the CME cloud is will improve estimates of the arrival time from within a day or so to just a few hours," said Howard. "STEREO also will help forecasters estimate how severe the resulting magnetic storm will be."

"In addition to the STEREO perspective of solar features, STEREO for the first time will allow imaging of the solar disturbances the entire way from the Sun to the Earth," said Dr. Madhulika Guhathakurta, STEREO program scientist at NASA Headquarters in Washington, DC.

Presently, scientists are only able to model this region in the dark, from only one picture of solar disturbances leaving the Sun and reaching only a fraction of the Sun-Earth distance.

As of today, five museums and planetariums across the United States are showing NASA's 3-D images of the Sun. They are the American Museum of Natural History's Hayden Planetarium in New York City through April 27; the Christa McAuliffe Planetarium in Concord, New Hampshire; the Maryland Science Center in Baltimore; the Adler Planetarium in Chicago; and the Denver Museum of Nature & Science. Check with each facility for the show's final date.

STEREO's first 3-D images are being provided by NASA's Jet Propulsion Laboratory in Pasadena, California.

STEREO is the third mission in NASA’s Solar Terrestrial Probes program within NASA’s Science Mission Directorate, Washington.

The Goddard Science and Exploration Directorate manages the mission, instruments, and science center.

The Johns Hopkins University Applied Physics Laboratory, Laurel, Maryland, designed and built the spacecraft and is responsible for mission operations.

The STEREO imaging and particle detecting instruments were designed and built by scientific institutions in the United States, the UK, France, Germany, Belgium, Netherlands, and Switzerland.

For sources of 3-D glasses, visit the NASA website at: