A New Spin On Earth

With an assist from digital technology, a spherical projection screen helps scientists teach us to understand our planet -- and others

May 26, 2006|By FRANK D. ROYLANCE | FRANK D. ROYLANCE,SUN REPORTER

First, there's the "Wow!" factor.

Visitors to the darkened Science on a Sphere Theater at the NASA Goddard Space Flight Center in Greenbelt are immediately awed by the glowing "planet" that appears to float three feet off the floor, spinning slowly in space.

"Oooh! Neat!" gushed a gaggle of second-graders from Crofton as they crowded the rail protecting the eerie, 6-foot orb.

As they watched, it transformed magically from a majestic, blue-green Earth to a rusty, barren Mars. A few youngsters reached out to see if it was solid, or an illusion of light -- a hologram.

The sphere, it turns out, is the least amazing part of the SOS Theater. It's a simple, 50-pound carbon-fiber globe, coated with white latex house paint -- a fixed, spherical movie screen suspended from three nearly invisible wires.

The real magic is in the four digital liquid crystal display projectors that illuminate it from the corners of the room, and in the software in the five computers that drive them. Together, they assemble real satellite images and scientific data into a graceful, spinning whole.

"This is a great way to understand what is happening to the globe, and to see and understand things like ocean currents," said Alexander E. "Sandy" MacDonald, the sphere's inventor. "People look at it and say, `Oh! That's how it works.' If you can visualize something, your understanding follows."

Scientists have been just as transfixed as the kids. Government research managers who gathered recently in Boulder, Colo., watched in rapt attention as a sphere at the Earth Systems Research Lab displayed the next 200 years of global warming with pulses of yellow and red.

MacDonald is acting director of the lab, which is part of the National Oceanic and Atmospheric Administration. "The Antarctic scientists were looking to see what happens at the South Pole; the tropical people were studying the tropics. ... They just kept saying, `Start it again, we want to see how these compare,'" MacDonald recalled.

"I had to drag them out of there," he added. "We see it as both a tremendous educational tool and also a tool for real scientists."

Gene Carl Feldman, an oceanographer at Goddard, said scientists need new ways to visualize the information they collect. "We are literally drowning in a sea of data," he said. "It's just overwhelming. The challenge is how do you take these bits coming down from space and convert them into something the human mind can deal with and see patterns in.

"Up 'til now, generally what we look at are big flat-screen presentations," he said. "But the Earth is not flat. It's round."

With data projected onto a globe, for example, the vastness of the Pacific Ocean and its influence on rainfall in the southeastern United States during an El Nino event becomes more obvious, he said.

MacDonald first conceived the sphere a decade ago. "I was driving down the road and I thought, `Why aren't we displaying stuff on spheres?'" he said.

So, he went home to his garage, painted a beach ball white and tried shining Apollo photos of the Earth onto it with a video projector. It worked well enough. But he sat on the idea for five years. "I thought it was so obvious that somebody must have done it," MacDonald said.

When no one did, he secured a patent on behalf of the federal government and built the first spherical projection system.

When a prototype version was installed two years ago for evaluation at the Maryland Science Center, "people just loved it," said the center's TerraLink manager, Katie Stofer. "People would stay longer at this than at other, different things."

The science center's SOS Theater opened May 4 as part of the permanent "Our Place in Space" installation. It's one of eight now up and running at museums across the country. There are plans for five more, but "boy, do we have a lot of global interest; we're getting calls from everywhere," MacDonald said.

The spherical display does best with spherical objects, such as planets and moons.

You can walk around the globe and watch as real hurricanes, recorded by NASA satellites, spin up on the Atlantic, crash ashore in the Gulf of Mexico and dissipate.

One visitor to Goddard remarked at how surprisingly small Hurricane Katrina looks when presented in its global context.

Other time-lapse sequences show the cycling of warm and cool sea-surface temperatures as El Nino and La Nina events pulsed across the Pacific Ocean; the seasonal advance and retreat of ocean plankton and snow and ice; and the nighttime illumination of the Earth's cities as seen from space.

Visitors can even watch satellite data showing the 2004 Indonesian tsunami as its ripples traverse every ocean on the planet, reaching Ocean City in 24 hours.

"It's so much easier to understand as a globe," said Roberta Cooks, senior director of exhibits at the science center.

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