The heliopause was expected to be a rather sharp boundary between the sun's domain and interstellar space.
太阳风顶层曾被认为是处在太阳系区域和星际宇宙之间一层电磁波动极其强烈的区域。
2
Many astronomers think that the limit of the heliosphere, known as the heliopause, is about 9 billion miles (15 billion kilometers) from the sun.
许多天文学家认为，日球层的边界是太阳风顶层，距离太阳90亿英里(150亿公里)。
3
Still operational, both Voyagers are headed towards the outer boundary of the solar system, in search of the heliopause and the beginning of interstellar space.