NASA Plans Light Shows to Test Earth’s Magnetism : Space: Experiments using barium and lithium will create moon-sized red and blue clouds visible from all of U.S.

NASA scientists are planning a series of spectacular light shows in the heavens over the next two weeks, creating brief moon-sized red and blue clouds in the moonless sky to study Earth’s magnetic fields.

They “will be the brightest feature in the sky, brighter than any star or planet,” said astronomer Richard Howard of the National Aeronautics and Space Administration. The clouds will look “sort of like a dimly lit moon or a moon seen through high clouds,” he said.

If conditions are right, the first of 15 canisters of chemicals will be released from a NASA satellite at 5:43 p.m. today. When released, the chemicals will be ionized by the sun’s ultraviolet light, creating large luminous clouds visible from all of North America, South America, the Caribbean and Western Europe.

“One-quarter of the world’s population will be able to see it,” said Howard, who is manager of the project.

In Southern California, the clouds should be visible in the southeast quadrant of the sky about 20 degrees above the horizon.

David S. Reasoner, the scientist in charge of the program, said the clouds will help improve the ability to predict disturbances in the oceans of invisible magnetic and electrical fields that surround the Earth.

The releases of the chemicals barium and lithium will be coordinated with aircraft and ground observations. They will be augmented by chemical releases from 10 sounding rockets launched from Puerto Rico and the Marshall Islands.

By observing the motion of the clouds, scientists can measure electrical fields in space to see how they interact with charged particles to form waves, and to better understand how Earth extracts energy from the solar wind emanating from the sun.

The $250-million Combined Release and Radiation Effects Satellite, containing 16 large chemical canisters and eight small canisters, was launched atop an Atlas rocket July 25 from the Cape Canaveral Air Force Station in Florida.

Tonight’s canister will be released at an altitude of 9,200 miles directly above a spot 420 miles east of San Juan, Puerto Rico.

Each cloud will begin as a bright pinpoint of light, spreading to full size in 30 seconds. The red barium clouds will be about one-third the size of the full moon and about one-tenth as bright. The blue-green lithium clouds will be about the size of the full moon.

Scientists won’t decide until 30 minutes before a planned release whether all conditions are right to proceed, Howard said.

The public can learn where the cloud can be seen by calling 1 (205) 544-5356.