New Space Show Dives into Sun
Unprecedented volume processing, both in time sampling and time span explored
|Visualization shows the generation of magnetic field in the solar convection zone and its connection to a sunspot at the visible surface of the Sun. Note that the sunspot (with a size slightly larger than Earth) is enlarged for better visibility and not in proper scale relative to the Sun. Courtesy of American Museum of Natural History|
The Hayden Planetarium’s new space show may be the most scientifically accurate and advanced planetarium show ever produced. Journey to the Stars, which debuted this summer at the American Museum of Natural History, features extraordinary images from telescopes on the ground and in space and stunning, never-before-seen visualizations of physics-based simulations. Narrated by Whoopi Goldberg, the 25-minute presentation takes viewers on a journey through the universe. It projects cutting-edge visualizations of the universe onto the 87-foot, seven-million-pixel dome of the museum’s Hayden Sphere at the Rose Center for Earth and Space in New York City.
Piecing together a new narrative of life’s origins, the space show explains how dark matter’s gravity gathered the primordial gas in the universe to form the first stars, and how these massive stars exploded, seeding the galaxy with new stars and the chemical elements that made life possible. The centerpiece of the show, and the most difficult sequence to depict scientifically, is a flight into the center of the Sun. The visuals of the Sun were produced using supercomputing resources provided by the NSF TeraGrid, a national cyberinfrastructure for open scientific research.
According to Ro Kinzler, the show’s producer, the production would not have been possible without the collaboration of the Texas Advanced Computing Center (TACC) and the National Center for Atmospheric Research (NCAR), two of 11 academic supercomputing centers that comprise the NSF TeraGrid.
“We wanted to treat the Sun in a terrific and powerful way to [not just] reveal the surface, but to take our audience into the Sun, through the convective layer and into the core,” Kinzler says. “The results are beautiful. No one has seen the Sun in this way, and the software from NCAR and computational resources from TACC made it possible.”
The visual sequences are based on the research of Juri Toomre, a professor of astrophysics at the University of Colorado at Boulder, and run on TACC’s Ranger supercomputer.
“It’s not enough to know what comes out of the surface,” Toomre says. “We would like to understand how the magnetic engine of a star works, how it churns away and how it builds orderly fields. This is one of the top 10 questions in physics.”
Toomre’s doctoral student Benjamin Brown used VAPOR (Visualization and Analysis Platform for Ocean, Atmosphere, and Solar Researchers), a tool developed by NCAR in collaboration with the University of California, Davis, and Ohio State University, to generate visualizations of the Sun and to create image sequences for the movie.
“VAPOR was a godsend for us,” says Carter Emmart, director of astrovisualization at the American Museum of Natural History. “It allowed us to see the data and provide editorial input before farming the data out to other means of visualizing in our production pipeline.”
Running 3-D simulations on Ranger, Brown made an unexpected discovery of wreaths of magnetism occupying a large portion of the inside of the Sun. Because they are within the upper 30 percent of the Sun — the convection zone — one can’t see these phenomena directly. However, the signature of these wreaths can be detected in the eruption of magnetic fields at the surface.
“This is unprecedented volume processing both in the time sampling and the time span being explored with this work,” says Brown. “Moving that amount of data back and forth between Ranger and the American Museum of Natural History was not a trivial endeavor.”
Numerical sunspot model
NCAR scientist Matthias Rempel also contributed to the movie using his recently developed numerical sunspot model to visualize the connection between the magnetic field in the solar interior and sunspots on the visible surface of the Sun. He customized a simulation for Journey to the Stars, processing approximately a terabyte of solar data on TACC’s Ranger supercomputer. Creating such detailed simulations would not have been possible before the latest generation of supercomputers and a growing array of instruments to observe the Sun, Rempel notes.
“I was very excited when I heard the Hayden Planetarium was interested in the sunspot visualization,” says Rempel. “If you do astrophysics, it’s a little detached from what people do in their normal lives, so it’s always a challenge to explain what you’re doing and why. Having an opportunity to show really interesting science through a planetarium show like this really helps a lot to give this message back to the public.”
“A very dramatic moment in the show is when we actually peel away the surface of the Sun, revealing the dynamic convective motion below,” Kinzler says. “We take the audience through the convective region and into the Sun’s core. The ability to go inside a star, made possible with the software from NCAR and computational resources from TACC, is central to the show’s goal to transform the audience’s view of stars from ‘pinpricks of light, shining in the velvety dark,’ to ‘super-hot churning balls of gas that generate just about every naturally occurring element in the universe.’ “
For additional information: http://www.amnh.org/rose/spaceshow/journey/