title: Earth's Bow Shock: Elapsed-Time Observations by Two Closely Spaced Satellites.
abstract: Coordinated observations of the earth's bow shock were made as Vela 3A and Explorer 33 passed within 6 earth radii of each other. Elapsed time measurements of shock motion give directly determined velocities in the range 1 to 10 kilometers per second and establish the existence of two regions, one of large amplitude magnetic "shock" oscillations and another of smaller, sunward, upstream oscillations. Each region is as thick as 1 earth radius, or more.
authors.forename: E W
authors.initials: EW
authors.lastname: Greenstadt
authors.forename: I M
authors.initials: IM
authors.lastname: Green
authors.forename: D S
authors.initials: DS
authors.lastname: Colburn