Direct Imaging of the Heliospheric Plasma Sheet from the SECCHI telescopes on the STEREO Mission

We report the first ever direct imaging observations of the fine scale structure of the solar wind in the inner heliosphere. The observations were obtained by the Sun-Earth Connection Coronal and Heliospheric Investigation (SECCHI) instrument suite on the Solar Terrestrial Relations Observatory (STEREO) mission. The SECCHI telescopes can trace the coronal plasma from its origins at the solar corona to the Earth's neighborhood. Besides coronal mass ejections, the images also reveal the fine scale structure of the heliospheric plasma sheet during quiet periods. Here, we will show the evolution of these structures from the inner corona to the inner heliosphere. We will also include comparisons with large-scale MHD models of the heliosphere and discuss the importance of such observations for understanding the physics of the solar wind.