A panel discussion is set up by including people with a variety of backgrounds and differing opinions on the subject at hand. The purpose is to create discussion about the topic and examine it from different points of view.
A panel discussion is usually made up of individuals who are experts in a topic of discussion. These experts often have contrasting ideas or different points of views.
A panel consists of an anchor, that runs the panel. Experts in the fields that relate to your particular topic but are not all same, and the people asking questions.
It depends on the scientific discussions you may need the opinion of exact group of scientists with the same backgrounds.If you just need an opinion it does not matter.