Ejecta

In volcanology, ejecta consists of particles that came out of a volcanic vent, traveled though the air or under water, and fell back on the ground surface or on the ocean floor. Ejecta can consist of

1. juvenile particles – (fragmented magma and free crystals)
2. cognate or accessory particles – older volcanic rocks from the same volcano
3. accidental particles – derived from the volcanic basement.

In planetary geology, ejecta can also refer to the debris that is ejected during the formation of an impact crater.

In astrophysics the term can refer to material expelled in a stellar explosion, like that described in The Plerionic Supernova Remnant G21.5–0.9: In and Out or (a detection by) The Advanced Satellite for Cosmology and Astrophysics (ASCA) http://heasarc.gsfc.nasa.gov/docs/asca/asca2.html