Magnetic field measurements by Voyager 2 reveal differences between the Uranian magnetopause and the typical terrestrial magnetopause. In particular there are pulsations in the magneic field at Uranus which may represent partial crossings of the magnetopause, the entry into magnetic flux ropes or the passage through mirror mode waves. Examination of terrestrial data especially those obtained under conditions of very high plasma beta suggests that the lase possibility is the more likely. The magnetopause crossing itself is also different than those typically observed at 1 AU. It contains a magnetic field rotation of over 270¿. While this is rare at 1 AU, an example has been found at Earth where the field rotation is also greater than 270¿. In some aspects these crossings resemble slow shocks. This also occurred at a time of high plasma beta. Thus we conclude that plasma beta is very important in determining the structure of the magnetopause. ¿ American Geophysical Union 1989