The spell might also end early for you or one of your companions. When the spell ends, the affected creature returns to its physical body, and it awakens. The spell ends for you and your companions when you use your action to dismiss it. Any damage or other Effects that apply to it have no Effect on your physical body, nor do they persist when you return to it. Your astral form is a separate incarnation. If you enter a new plane or return to the plane you were on when casting this spell, your body and possessions are transported along the silver cord, allowing you to re-enter your body as you enter the new plane. Your astral form can freely Travel through the Astral Plane and can pass through Portals there leading to any other plane. If the cord is cut-something that can happen only when an Effect specifically states that it does-your soul and body are separated, killing you instantly. As long as the tether remains intact, you can find your way home. This cord is your tether to your material body. The principal difference is the addition of a silvery cord that extends from between your shoulder blades and trails behind you, fading to Invisibility after 1 foot. Your astral body resembles your mortal form in almost every way, replicating your game Statistics and possessions.

The material body you leave behind is Unconscious and in a state of suspended animation, it doesn't need food or air and doesn't age. You and up to eight willing creatures within range project your astral bodies into the Astral Plane (the spell fails and the casting is wasted if you are already on that plane).

How to do astral projection