This is the fourth of the four pillars of the planet Cassiopeia.
"The Cassiopeia mission aimed to find the source of radar signals coming from this planet. Abandoned for centuries, we found nevertheless four massive pillars which continue to emit strange radio wave, we did not know how to decipher it yet. But each pillar is located at a particular point of the planet, and is connected to the others by a whole network of luminous roots.
As evidenced by the vegetation embedded in these pillars, it would seem that this civilization has managed to use nature as a technology. Why the planet seems to be abandoned is beyond us at the moment, but it seems obvious that these signals have remained a...