The Scale of the Heliosphere and Nearby Galactic Neighborhood


The solar system and its nearby galactic neighborhood are illustrated here on a logarithmic scale extending (from < 1 to) 1 million Astornomical Units (AU). Our Sun and its planets are shielded by a bubble of solar wind - the heliosphere - that is about 100 AU in size. The actual boundary between solar wind and interstellar plasma is called the heliopause. Beyond this bubble is a largely unknown region - the interstellar medium. Threaded through the boundaries of the heliosphere is the Kuiper Belt - the source of short-period comets. The nearest edge of the interstellar cloud that presently surrounds our solar system is thought to be several thousand AU away. The Oort Cloud is a spherical shell of comets extending from <10,000 to ~100,000 AU - the edge of our Sun's gravitational spere of influence. Alpha-Centauri, the best known member of our nearest star system, lies well beyond at ~300,000 AU. Interstellar Probe is to be man's first spacecraft designed to exit the heliosphere and begin the exploration of the interstellar medium.


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Introduction
Interstellar Medium
Interaction Between the Interstellar Medium and the Solar Wind
The Outer Solar System
Scientific Instruments and Mission Requirements
Acknowledgments
Table of Contents


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and the Interstellar Probe Project,
please contact Dr. Paulett Liewer

This site was last updated:
February 8, 2000.