For many years, the idea that coronal mass ejections (CME) launched from the Sun and could strike the Earth was inferred from an indirect chain of evidence collected from multiple satellites. Now the Heliospheric Imagers aboard the STEREO-A spacecraft has managed to view a CME propagate from the surface of the Sun to the Earth.
This visualization shows the position of the STEREO spacecraft during the event, as well as the positions of the inner solar system planets, Venus and Mercury. A faint cone illustrates the field-of-view (FOV) of the HI-2 imager on STEREO-A. The position of the front of the CME is computed from STEREO data.
GCMD keywords can be found on the Internet with the following citation:
Olsen, L.M., G. Major, K. Shein, J. Scialdone, S. Ritz, T. Stevens, M. Morahan, A. Aleman, R. Vogel, S. Leicester, H. Weir, M. Meaux, S. Grebas, C.Solomon, M. Holland, T. Northcutt, R. A. Restrepo, R. Bilodeau, 2013. NASA/Global Change Master Directory (GCMD) Earth Science Keywords. Version 184.108.40.206.0