By Sean Henahan, Access Excellence

SAN FRANCISCO (DEC. 16, 1996) A certain jolly old elf and his reindeer may be able to steer around magnetic storms thanks to a new kind of high resolution images of the near-Earth space environment provided by the NASA POLAR scientific satellite.

The first of these images ever seen were debuted at a meeting of the American Geophysical Union here.

Image: POLAR Weather Report

"For the first time ever we can produce high resolution images or "snapshots" of our atmosphere. We can view them singly or combine them to make movies which allows us to track magnetic storms in the space just outside the Earth's atmosphere," says Dr. Harlan E. Spence, assistant professor of astronomy at Boston University and lead investigator on the project.

"From these images we can begin to answer fundamental questions about the relationship between Earth and the Sun, and how our near-Earth space environment responds to eruptions on the Sun to produce space weather."

Space weather is created when the energetic charged particles and magnetic fields of the Sun blow past and meet the magnetic field of the earth. The interaction of these energy fields can produce magnetic storms in space which in turn create dazzling effects in the atmosphere such as the aurora borealis, or "northern lights." On the negative side, it can also affect or damage satellites used for communication, navigation and weather prediction.

"We have learned much over the last three decades about the particles populating space near Earth and how they change during magnetic storms. Until now, however, we have been severely limited in our ability to simultaneously sample large regions of space to get the 'big picture.' The new images are unprecedented in their capacity to provide that fresh perspective needed to really push the frontiers of new knowledge," says Dr. Theodore A. Fritz, professor of astronomy at Boston University and coprincipal investigator.

The NASA POLAR spacecraft was launched into Earth orbit in late February 1996 carrying a new kind of instrument called an Imaging Proton Spectrometer (IPS). The IPS records energetic neutral atoms (ENAs) to produce the images. ENAs are created when the cold neutral gases of the atmosphere interact with the very energetic charged particles trapped in the Van Allen radiation belts which encircle the Earth's equatorial region at high altitudes (~10,000 km). They are detected by the IPS from even higher altitudes (~50,000 km) over the earth's northern geographic pole. Large numbers of ENAs are produced during periods of increased Van Allen belt intensity, called magnetic storms, which are associated with solar eruptions, called coronal mass ejections.

Although no large magnetic storms have occurred thus far during the POLAR mission, several smaller storms have already produced significant ENA events which lead investigators to believe that even better images will be obtained.

"The POLAR mission is part of a larger international program to study the complex connections between the Sun as a star and the Earth as a planet," says Dr. Robert Hoffman, the POLAR Project Scientist at the NASA Goddard Space Flight Center which supports the mission. "The ENA images from POLAR are an exciting new way of visualizing an important aspect of this crucial interaction".

POLAR movies and images may be found at the POLAR web site http:// leadbelly.lanl.gov/ccr/CCR.html