DEFORMED SHAPE. “In the antisunward direction, the solar wind flow deforms the dipolar magnetic field to a cometary taillike shape where the magnetopause is on average about 30 RE from the Sun-Earth line, depending on the solar wind pressure. The magnetotail extends far beyond lunar orbit at least a few hundred RE in the antisunward direction.”
https://link.springer.com/article/10.12942/lrsp-2007-1