NASA Mission Shows Evolution Of Conditions At Edge Of Solar System

The IBEX has produced a new set of "all-sky" maps of our solar
system's interaction with the galaxy, allowing researchers to
continue viewing and studying the interaction between our galaxy and
sun. The new maps reveal changing conditions in the region that
separates the nearest reaches of our galaxy, called the local
interstellar medium, from our heliosphere -- a protective bubble that
shields and protects our solar system.

In October 2009, scientists announced that the first map data produced
by IBEX revealed an unpredicted bright ribbon of energetic neutral
atoms emanating toward the sun from the edge of the solar system.
This discovery was unexpected to scientists, because the ribbon of
bright emissions did not resemble any previous theoretical models of the region.

The IBEX spacecraft creates sky maps by measuring and counting
particles referred to as energetic neutral atoms that are created in
an area of our solar system known as the interstellar boundary
region. This imaging technique is required since this region emits no
light that can be collected by conventional telescopes. This
interstellar boundary is where charged particles from the sun, called
the solar wind, flow outward far beyond the orbits of the planets and
collide with material between stars. These collisions cause energetic
neutral atoms to travel inward toward the sun from interstellar space
at velocities ranging from 100,000 mph to more than 2.4 million mph.

This second set of all-sky maps, created using data collected during
six months of observations, show the evolution of the interstellar
boundary region. The maps help delineate the interstellar boundary
region, the area at the edge of our solar system that shields it from
most of the dangerous galactic cosmic radiation that would otherwise
enter from interstellar space. The new findings were published this
week in the Journal of Geophysical Research - Space Physics, a
publication of the American Geophysical Union.

"Our discovery of changes over six months in the IBEX ribbon and other
neutral atoms propagating in from the edge of our solar system show
that the interaction of our sun and the galaxy is amazingly dynamic,"
said David J. McComas, IBEX principal investigator and assistant vice
president of the Space Science and Engineering Division at Southwest
Research Institute in San Antonio. "These variations are taking place
on remarkably short timescales."

The IBEX spacecraft was launched in October 2008. Its science
objective was to discover the nature of the interactions between the
solar wind and the interstellar medium at the edge of our solar system.

"This situational awareness provided by IBEX shows our place in space
is not constant," said Dick Fisher, director of the Heliophysics
Division in NASA's Science Mission Directorate at the agency's
Headquarters in Washington. "Better understanding of the dynamic
environment of space is vital for successful planning for future
exploration." The goal of the Heliophysics Division is to understand
the sun and its interactions with Earth and the solar system.

The Southwest Research Institute developed and leads the IBEX mission
with a team of national and international partners. The spacecraft is
one of NASA's series of low-cost, rapidly developed missions in the
Small Explorers Program. NASA's Goddard Space Flight Center in
Greenbelt, Md., manages the program for the agency's Science Mission
Directorate.

For more information about IBEX, visit:

http://www.nasa.gov/ibex

Source: NASA

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