NASA's IBEX provides first glimpse of solar system's comet-like tail
Sunday, July 14, 2013, 8:07 - The solar system has a tail and for the first time NASA's Interstellar Boundary Explorer (IBEX) has provided a glimpse of the feature that scientists long believed was there but could never see.
NASA this week is heralding the first glimpse of something they've long suspected existed but could never see - the solar system's tail.
For years scientists have hypothesized that the solar system had a tail -much like a comet - that left particles behind as it moved through space.
The discovery was made through three years worth of observations from IBEX.
Data was analyzed and when mapped, showed a combination of fast and slow moving particles.
The complete findings were published last month in the Astrophysical Journal.
“By examining the neutral atoms, IBEX made the first observations of the heliotail,” said David McComas in a release, lead author on the paper and principal investigator for IBEX at Southwest Research Institute in San Antonio, Texas. “Many models have suggested the heliotail might be like this or like that, but we’ve had no observations. We always drew pictures where the tail of the heliosphere just disappears off the page, since we couldn't even speculate about what it really looked like.”
Scientists describe our solar system much like a meteor moving through the earths atmosphere. A meteor leaves a trail as it begins to burn up while the solar system leaves a stream of particles trailing off behind it.
The new map showing the tail features two lobes of slower particles on the sides, while faster moving particles form at the top and bottom. The entire structure twists as magnetic fields outside the solar system push and pull at it.
The tail is called a "heliotail" by scientists because it follows the heliosphere - also known as the "Solar Bubble" - an area of charged particles surrounding the solar system which is heavily influenced by the sun.
Scientists had discovered tails around other stars but had difficulty seeing one with our sun.
In 1983, Pioneer 10 came close to seeing one as it crossed the orbit of Neptune but unfortunately it lost power 20 years later, before it moved into the tail. No data was recovered from the probe.
Seeing the particles conventionally is difficult because they do not shine but IBEX can still map such regions.
Using a technique called "energetic neutral atom imaging," it measures neutral particles created by collisions along the heliosphere’s boundaries.
For Eric Christian, IBEX mission scientist at NASA’s Goddard Space Flight Center, the discovery helps teach more about the solar wind that blows from the sun.
"IBEX scans the entire sky, so it has given us our first data about what the tail of the heliosphere looks like, an important part of understanding our place in and movement through the galaxy,” said Christian in a release. He added: “The tail is our footprint on the galaxy, and it’s exciting that we’re starting to understand the structure of it.”
Scientists still do not know how long the tail is.
They hope to use their new observations in conjunction with computer simulations of the heliosphere to expand their models.