The CME studied was ejected from the Sun on 19 March 2010, when the STEREO A spacecraft was in a position to watch from the side as the CME hurtled outwards towards the Earth. The structure of the CME was examined in HI images spanning a distance of approximately 48 million km at different distances between the Sun and the Earth. Analyzing the images indicated that its speed was close to 350 km per second, which allowed its time of impact on the Earth to be predicted some 3 days after the initial ejection.
The results indicate that the CME structure evolves considerably on its outward journey, and that the internal structure can be difficult to predict from the images. And there is another key facet to this work —
Source: Royal Astronomical Society
The aim of art is to represent not the outward appearance of things, but their inward significance. – Aristotle