1. There are several traits that heroes tend to share. First of all, heroes tend to be selfless, and to care deeply about others. This is the main reason why they are willing to put themselves at risk in order to help others. Moreover, heroes are brave, even when they are scared. Heroes are also empathetic and kind. Heroes tend to be intelligent, and they usually complete their missions thanks to a combination of strength and intelligence.
2. A person who could be a hero today would be someone in a mission that employs all these characteristics to suceed. An example would be activist Greta Thunberg. In her recent journey to New York across the ocean, she showed that she was brave and strong. She has also shown that she is willing to go to great lengths in order to achieve her mission and help the world.
3. I do not notice any specific differences between heroes of the past and heroes of the present. In general, heroes have always shared the same characteristics.