We currently do not delete accounts. Additionally, we do not allow players to reset their game progress. If that is what you were hoping to accomplish by deleting your account, that won't be possible.
If you do not log in for at least 30 days your base will automatically be reaped from the map, though there is a chance it might be removed a little sooner than that should a large number of players wish to move to your current planet. This will ensure that you will no longer be present in game. If you ever wish to return, you can log back into your account and this will automatically place you back on the map with the base level the same as when you left.