Mapping out the heliosphere, Earth’s protective bubble

Much as we may treasure and proclaim our independence, we actually live in a protective bubble called the heliosphere.

This extraordinary environment is basically the sun's sphere of influence. It surrounds our solar system and shields it from galactic cosmic radiation that comes mostly from outer space - rays that travel near the speed of light. The Earth's magnetic field also protects us from incoming radiation.

The heliosphere is an electro-magnetic environment, inflated by the solar wind - the stream of high-energy particles (protons, ions and electrons) that the sun constantly shoots out at speeds often greater than 1 million miles per hour.

We're about to learn much more about this region, when NASA's IMAP (Interstellar Mapping and Acceleration Probe) spacecraft is launched on a SpaceX Falcon 9 rocket next week from Kennedy Space Center in Florida. IMAP has a suite of 10 instruments that will measure the solar wind, plasma, high-energy particles and electromagnetic fields for monitoring space weather, which can have great impact on astronauts, satellites and telecommunications systems.

One of our planet's great experts on the heliosphere and the solar wind is William H. Matthaeus, the Martin Pomerantz Professor of Physics and Astronomy at the University of Delaware. Earlier this year, Matthaeus was elected to membership in the National Academy of Sciences, one of the highest honors a scientist can receive.

Matthaeus helped to shape the scientific questions, calculations and specifications related to the magnetic field instrument that laid the foundation for IMAP and is a co-investigator. His primary contributions relate to magnetic field turbulence near the Earth, plasma velocities and temperatures near the Earth.

During its two-year journey, IMAP will investigate two primary issues - how the charged particles from the sun get so much energy and how the entire solar system interacts with interstellar space. It will also measure and study the fine particles known as cosmic dust that originates from outside the solar system.

The project, led by Princeton University's Professor David J. McComas and managed by the Johns Hopkins Applied Physics Laboratory, also includes other universities and industries from around the U.S., 82 partners in all.

"We are going to find incredible new discoveries," said Nicky Fox, associate administrator for NASA's Science Mission Directorate, during a media briefing earlier this month. "What is coming from the sun? What is coming from the interstellar medium? We're excited about the applications.

"But the actual discovery science is going to literally rewrite textbooks and that's why we're so excited about it."

Matthaeus agrees.

"We intend to be part of that rewrite," Matthaeus said, "not just me, but my students and postdocs. I always tell them, 'Don't just look over your shoulder. Try to do something nobody else has done before.'"