"Eject items from your cargo hold onto a planet. Hold to drop creatures gently."
This tool is added to your inventory after you have completed the basic mission. It is used to abduct items, and also to drop items after you have clicked on them. When you dropping items, you are disposing of all of that item in your inventory. You can only use this tool when you are on a planet. When you are in space, you must go to your inventory and click the X on the item, and a message will come up, and it will look like this: "Do you want to permanantly jettison this item from your cargo?"
This tool is available at the beginning of the game.