National Aeronautics and Space Administration Logo
Follow this link to skip to the main content NASA Banner
Solar System Exploration
News & Events
NASA Voyager Statement About Solar Wind Models
NASA Voyager Statement About Solar Wind Models
23 Jul 2014
(Source: Jet Propulsion Laboratory)

Illustration of Voyager spacecraft in deep space.
This artist's concept depicts NASA's Voyager 1 spacecraft entering interstellar space, or the space between stars.

A paper recently published in the journal Geophysical Research Letters describes an alternate model for the interaction between the heliosphere -- a "bubble" around our planets and sun -- and the interstellar medium. It also proposes a test for whether Voyager 1 has, indeed, left the heliosphere.

NASA's Voyager project scientist, Ed Stone of the California Institute of Technology in Pasadena, responds:

"It is the nature of the scientific process that alternative theories are developed in order to account for new observations. This paper differs from other models of the solar wind and the heliosphere and is among the new models that the Voyager team will be studying as more data are acquired by Voyager."

Stone went on to explain that other models, which he and colleagues used to conclude that Voyager 1 entered interstellar space, predict that the density of interstellar wind outside the heliosphere is 40 times greater than the density of the solar wind inside.

Voyager scientists had carefully analyzed the observational data from the spacecraft, which revealed a plasma density that was 40 times higher. They then concluded that Voyager 1 had departed the solar bubble and entered interstellar space around August 25, 2012.

But the new article argues that solar wind inside the heliosphere can be compressed to the point that the solar wind density inside is just as high as interstellar space outside. Therefore, Voyager 1 could still be inside.

Authors of the new study predict that if Voyager 1 is still inside the heliosphere, the spacecraft will observe a reversal in direction of the solar magnetic field sometime before the end of 2015. Stone said he and colleagues will be looking carefully at the magnetic field data over the coming 18 months to see if Voyager picks up this change.

The Voyager spacecraft were built and continue to be operated by NASA's Jet Propulsion Laboratory, in Pasadena, California. Caltech manages JPL for NASA. The Voyager missions are a part of NASA's Heliophysics System Observatory, sponsored by the Heliophysics Division of the Science Mission Directorate at NASA Headquarters in Washington.

For more information about Voyager, visit:

http://www.nasa.gov/voyager

http://voyager.jpl.nasa.gov


2014-238

Elizabeth Landau
NASA's Jet Propulsion Laboratory, Pasadena, Calif.
818-354-6425
Elizabeth.Landau@jpl.nasa.gov

News Archive Search  Go!
Show  results per page
 
 
Awards and Recognition   Solar System Exploration Roadmap   Contact Us   Site Map   Print This Page
NASA Official: Kristen Erickson
Advisory: Dr. James Green, Director of Planetary Science
Outreach Manager: Alice Wessen
Curator/Editor: Phil Davis
Science Writer: Autumn Burdick
Producer: Greg Baerg
Webmaster: David Martin
> NASA Science Mission Directorate
> Budgets, Strategic Plans and Accountability Reports
> Equal Employment Opportunity Data
   Posted Pursuant to the No Fear Act
> Information-Dissemination Policies and Inventories
> Freedom of Information Act
> Privacy Policy & Important Notices
> Inspector General Hotline
> Office of the Inspector General
> NASA Communications Policy
> USA.gov
> ExpectMore.gov
> NASA Advisory Council
> Open Government at NASA
Last Updated: 23 Jul 2014