Five spacecraft observations of oppositely directed exhaust jets from a magnetic reconnection X-line extending > 4.26 × 10⁶ km in the solar wind at 1 AU

Observations of oppositely directed plasma jets within an extended, bifurcated current sheet in the solar wind by a flotilla of five well-separated spacecraft (STEREO A and B, ACE, Wind and Geotail) on 11 March 2007 demonstrate that magnetic reconnection X-lines in the solar wind can extend to distances at least as great as 4.26 × 106 km (0.0284 AU) in the presence of a significant and variable guide field. The observations also indicate that reconnection in the solar wind can persist for at least 5 hours and 20 minutes. These minimum values are the largest yet obtained from direct measurements of reconnection exhaust flows in a space plasma. Both dynamic processes in the reconnection region and the spherical expansion of the solar wind probably contribute to the production of long X-lines in the solar wind.