First sky map of the solar system in our galaxy

NASA's IBEX probe delivers spectacular data from the solar-space-space interface

Sky map of the heliosphere, the boundary layer of our solar system. © NASA / Goddard Space Flight Center Scientific Visualization Studio
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The first comprehensive map of our solar system and its border region to the rest of our galaxy has now been delivered by the NASA satellite "IBEX". They show a whole new picture of the boundary of our solar system and also mean that many theoretical models now have to be rewritten. As many as six articles in the current issue of Science magazine are dedicated to these new findings.

Although we have already sent numerous space probes into space, we have almost never reached the limits of our solar system. No wonder, the distance is extreme: The distance is extreme: more than 10 high 10 kilometers - this corresponds to 100 times the distance between earth and sun, this limit is removed. Only the two 1977 launched Voyager probes have reached the outermost part of the planetary system after about 30 years of flying time.

From Earth orbit to the limit of the system

Now NASA has developed a new option, the Interstellar Boundary Explorer (IBEX), which does not require decades of travel to the edge of the solar system: IBEX explores the boundary between our solar system and interstellar space from Earth orbit. In this boundary layer, the hot solar wind and the cold interstellar matter, a mixture of gas and dust, meet and mix. The solar wind forms a protective bubble - the heliosphere - which surrounds our solar system and shields it from part of the cosmic radiation.

Bright band marks the border

With the help of two sensors, "IBEX-Hi" and "IBEX-Lo", the distribution of different particles across the boundary layer has been mapped over the last six months. In the process, a large accumulation of electrically neutral atoms was discovered, which arise from the collision of charged particles in the solar wind and interstellar matter. This collection of neutral particles runs as a bright band through almost the entire boundary layer, which can not be seen with conventional telescopes.

Movement direction of the sun (violet arrow) in front of the boundary layer map NASA / Goddard Space Flight Center Scientific Visualization Studio

Sky map of the nearest surroundings

This results in a completely new physical picture of the boundary of our solar system quasi a sky map of our closest surroundings. "For the first time, we've taken our heads out of the sun's atmosphere and are beginning to really understand our place in the galaxy, " explains David J. McComas, scientific director of IBEX Mission and scientists at the Southwest Research Institute in San Antonio. The IBEX results are truly remarkable, with no trace of bright details or emissions similar to any of the current theoretical models in the region. Display

Theories have to be modified

In the last 40 years, there were virtually only computer simulations and theories about the boundary layer of our solar system, because experimental clues were largely missing. Many entries for IBEX were based on theoretical assumptions about the physical conditions there. The measurements now show a completely different picture. We must massively revise our assumptions, "explains Professor Peter Wurz of the Institute of Physics at the University of Bern, which was involved in the development of the sensors.

Thus the magnetic field of interstellar matter is recognizable on the sky maps. The strength and direction of this magnetic field can now be determined by new model calculations. These in turn enable accurate computer simulations of the processes there. "It will be exciting years of data analysis approaching us. For the first time measurements have been taken on physical processes from the edge of our solar system, and we Berner will participate in it, "says Wurz.

Voyager probes overlook the bright band

The IBEX sky maps also provide the context for the observations of the two Voyager probes traveling in this area. Both have reached the area where the energetically neutral atoms are located but could not detect the bright band. "The Voyagers deliver the most accurate data, but they miss the most exciting region, " explains Eric Christian, an IBEX project researcher at NASA's Goddard Space Flight Center in Greenbelt. "It's like having two weather stations overlooking the big storm that is taking place between them."

(NASA / University of Bern, October 16, 2009 - NPO)