Artist's impression

An artist's impression or artist's interpretation is the representation of an object or a scene created by an artist, when no other accurate representation is available. It could be an image, a sound, a video or a model. Artist's impressions are often created to represent concepts and objects that cannot be seen by the naked eye; that are very big, very small, in the past, in the future, fictional, or otherwise abstract in other ways. For example, in architecture, artists' impressions are used to showcase the design of planned buildings and associated landscape.

Artist's impression of the unique rocky comet C/2014 S3 (PANSTARRS).

An artist's rendering of a planned building

An artist's impression of exoplanet HD 189733 b (video)

A Chinese artist's impression of Jesus

This artist’s impression shows how Mars may have looked about four billion years ago

...
Wikipedia