The image shows a large billboard in a subway station. The billboard is blue in color and has the words "Astronomía 2018" written in white letters at the top. Below the text, there is an illustration of a large telescope with a blue background. The telescope is surrounded by a network of lines and dots, representing the solar system. 

On the right side of the billboard, there are two men walking past it. The man on the left is wearing a yellow t-shirt and carrying a bag, while the man in the yellow shirt is walking past the billboard. The date "19:23 de marzo" is written in red letters on the bottom right corner.

The billboard appears to be promoting an event or event related to astronomy.