If you have a show, platform, audience and happen to interview someone great in a certain field or expertise or even just entertainment, you've got to have a skill. That skill is the art of asking the right questions, otherwise, you won't have the attention to keep what you're doing going on for long. This skill ensures longevity.
First of all, you have to be prepared. You can't just pop out questions from your mind without having an objective. Some interviews could be structured in a way to educate, enlighten or just create awareness. For that reason, you have to do a background check on the person you are interviewing.
Thereafter, you have to do some digging and be informed about the topic you will be discussing. Failure to do so will lead to mediocre questions and this is not pleasant to the interviewee or your audience. I mean, you can even lose the chance of hosting that person for a second time or having any referrals from him/her. Do not come off as a time waster for being ignorant.
You then have to own the show, be passionate about it and moderate it in such a way that creates positive energy to everyone participating and watching. If you have a panel interview, give everyone a chance to respond and address them by their names, that way it shows you are interested not just in getting the questions out of the way but engaging with them on a personal and professional level.
The truth is, the art of asking the right questions is not necessarily something that can be taught in school, you either have it in you and learn along the way, or you don't. Take time to practice even with your peers or when just having normal conversations. With time you will be able to perfect this art if you do it more often.