Scientists accurately simulate appearance of sun's corona during eclipse

Jun 26, 2006
Scientists accurately simulate appearance of sun's corona during eclipse
Scientists simulated the appearance of the Sun's corona during a March, 2006, solar eclipse. Credit: Science Applications International Corporation and NASA

The most true-to-life computer simulation ever made of our sun's multimillion-degree outer atmosphere, the corona, successfully predicted its actual appearance during the March 29, 2006, solar eclipse, scientists have announced.

The research, funded by NASA and the National Science Foundation (NSF), marks the beginning of a new era in space weather prediction. The results are presented today at the American Astronomical Society (AAS)'s Solar Physics Division meeting in Durham, N.H.

"This confirms that computer models can describe the physics of the solar corona," said Zoran Mikic of Science Applications International Corporation (SAIC), San Diego, Calif.

The turbulent corona is threaded with magnetic fields generated beneath the visible solar surface. The evolution of these magnetic fields causes violent eruptions and solar storms originating in the corona.

Like a rubber band that's been twisted too tightly, solar magnetic fields suddenly snap to a new shape while blasting billions of tons of plasma into space, at millions of miles per hour, in what scientists call a coronal mass ejection (CME). Or the magnetic field explodes as a solar flare with the force of up to a billion 1-megaton nuclear bombs.

When directed at Earth, solar flares and CMEs can disrupt satellites, communications and power systems.

"Finding out that a hurricane is bearing down on you isn't much good if the warning only gives you an hour to prepare," said Paul Bellaire, program director in NSF's Division of Atmospheric Sciences, which funded the research. "That's the situation we're in now with space weather. Being able to determine the structure of the solar wind at its source -- the sun -- will give us the lead time we need to make space weather predictions truly useful."

By accurately simulating the behavior of the corona, scientists hope to predict when it will produce flares and CMEs, the same way the National Weather Service uses computer simulations of Earth's atmosphere to predict when it will produce thunderstorms or hurricanes.

The computer model was based on spacecraft observations of magnetic activity on the sun's surface, which affects and shapes the corona above it. The SAIC team released simulated "photographs" of the March 29 eclipse 13 days and again 5 days before the eclipse.

During a total solar eclipse, the moon blocks direct light coming from the sun, so the much fainter corona is visible, resembling a white, lacy veil surrounding the black disk of the moon. That is the only time the corona is visible from Earth without special instruments.

Because the corona is always changing, each eclipse looks different. The simulated photographs closely resembled actual photos of the eclipse, "providing reassurance that the model may be able to predict space weather events," said Mikic.

Previous simulations were based on simplified models, so the calculations could be completed in a reasonable time by computers available then. The new simulation is the first to base its calculations on the physics of how energy is transferred in the corona.

Even with today's powerful computers, the calculations required four days to complete on about 700 computer processors.

Source: National Science Foundation

Explore further: Will NASA's TESS spacecraft revolutionize exoplanet hunting?

add to favorites email to friend print save as pdf

Related Stories

SOHO and Hinode offer new insight into solar eruptions

Jan 23, 2015

The sun is home to the largest explosions in the solar system. For example, it regularly produces huge eruptions known as coronal mass ejections – when billions of tons of solar material erupt off the sun, ...

Will the real monster black hole please stand up?

Jan 08, 2015

(Phys.org)—A new high-energy X-ray image from NASA's Nuclear Spectroscopic Telescope Array, or NuSTAR, has pinpointed the true monster of a galactic mashup. The image shows two colliding galaxies, collectively ...

Image: Solar coronal hole welcomes the new year

Jan 05, 2015

There were no fireworks on the sun to welcome in the New Year and only a few C-class flares during the last day of 2014. Instead, the sun starts 2015 with an enormous coronal hole near the south pole. This ...

Proba-3 double-satellite nearer to space

Dec 09, 2014

A pair of satellites flying in close formation to cast an artificial eclipse is now being turned into space-ready reality by ESA's industrial partners.

Sun sizzles in high-energy X-rays

Dec 23, 2014

For the first time, a mission designed to set its eyes on black holes and other objects far from our solar system has turned its gaze back closer to home, capturing images of our sun. NASA's Nuclear Spectroscopic ...

Recommended for you

VLT image: The mouth of the beast

3 hours ago

Like the gaping mouth of a gigantic celestial creature, the cometary globule CG4 glows menacingly in this new image from ESO's Very Large Telescope. Although it appears to be big and bright in this picture, ...

User comments : 0

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.