Astronomy is in many ways unique among the sciences due to its largely observational nature. Astronomical data are collected inside and outside of the visual spectrum, and an astronomer’s job then becomes one of producing meaningful representations to represent the new knowledge that can be extracted from this data. In this presentation, we will look at Astronomy under this scope: social semiotics, which stands for the study of signs and how they are created and reproduced within particular social groups for meaning-making purposes. For the purposes of this talk, we will treat Astronomy representations (diagrams, images, equations) as objects placed in the space between people in order to achieve communication. Using this approach in Astronomy Education Research, we manage to uncover crucial disciplinary aspects of these representations and understand how to use them more effectively in Astronomy Teaching & Learning. Furthermore, we will look at some examples of how we apply this approach to specific astronomy representations: we will demonstrate how we can use this framework to better understand the particularities of the Hertzsprung-Russell diagram and what makes it difficult for students to interpret, we will look at how we use mathematics in astronomy for meaning making purposes and lastly, we will use the map of the Cosmic Microwave Background (CMB) radiation to uncover some aspects that Astronomy experts see in representations, without them being directly visible. This is a crucial part of the nature of expertise in any scientific discipline, and a fundamental goal for Astronomy teaching & learning: the question of how to introduce a newcomer (a student) to Astronomy becomes a question of how to make them see what an expert sees in Astronomy representations.