Depending on which management writer was asked, the visitors from space would be directed to different people. These writers seem to have different definitions of leadership and thus leaders. Some simplify it to 'leadership is about dong the right things, while management is about doing things right."
Leadership is about doing the right things. Not really,
Leadership is about having a vision. Not really, everyone has visions and dreams.
Leadership is about a charismatic and powerful personality. Not really, there are charismatic and powerful personalities who are not leaders (almost every movie celebrity)
Leadership is a process, influencing others to perform something. Like selling or marketing or mugging?
Leadership is about authority and power. There are many people in positions of authority who cannot command.
My current view is that leadership is about having followers. Without any followers, you are not a leader. That is all it is. To take the lead means to be the leader. Without followers there is not lead to take.