Are the Heliosphere, Very Local Interstellar Medium, and Local Cavity in Pressure Balance with Galactic Gravity?*

The Voyager spacecraft are providing the first in situ measurements of physical properties in the outer heliosphere beyond the heliopause. These data, together with data from the IBEX and Hubble Space Telescope and physical models consistent with these data, now provide critical measurements of pressures in the heliosphere and surrounding interstellar medium.