• In volcanology, particles that came out of a volcanic vent, traveled through 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 rocks under the volcano.
• In planetary geology, the debris that is ejected during the formation of an impact crater.
• In astrophysics, material expelled in a stellar explosion.
• In firearms ballistics, everything expelled from a gun, including the bullet, propellant, sabot, wad, etc.

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