SMCAS

Oct 3rd 2008

Dr. Phil Scherrer

Think of the sun as an acoustic instrument with sound waves continuously rebounding around inside, the way seismic waves reverberate inside Earth. The speed and other characteristics of the waves offers indications of the flows beneath the surface, possibly identifying precursor events that could provide advance warning of dangerous solar storms and sunspots.

The study of these waves is the science known as helioseismology, and it is no small task. "It's like deducing the interior structure of a piano by listening to it fall down a flight of stairs," Dr. Scherrer says. The HMI (Helioseismic and Magnetic Imager), to be launched in December 2008, will give scientists a new ear to listen in on the sun, who can then give the earth and astronauts a better early warning system of potential danger. In his presentation, Dr. Scherrer will tell us about the future of helioseismology.

The Helioseismic and Magnetic Imager (HMI) investigation, is based on measurements obtained with the HMI instrument as part of the Solar Dynamics Observatory (SDO) mission scheduled to launch in December 2008. The goal is to study the origin of solar variability and to characterize and understand the Sun's interior and the various components of magnetic activity.

When an Atlas V missile finally lofts the HMI into geosynchronous orbit 22,500 miles above Earth, it will, with total disregard for the usual parental advice, stare directly into the sun. For several years it will record, in unprecedented detail, the behavior of powerful magnetic fields in the sun and the subtle surface undulations that surrender information about crucial activity deep within. Every two seconds, for at least five years, HMI will snap a high-resolution image and download it to a radio link in New Mexico.

The HMI was designed in collaboration with Dr Philip Scherrer, HMI Principal Investigator, and other scientists at Stanford University.  Dr Scherrer earned his Ph.D. in Physics at the University of California at Berkeley.



Tom Nichols, a mechanical engineer at Lockheed Martin in Palo Alto, works on the HMI. (Credit: Russ Underwood/Lockheed Martin)