This is a setting based on the book by Ray Bradbury of the same name. This is present day Earth and the Solar System with one small difference, we are substituting the Mars from the Martian Chronicles. This Mars has an advanced if decaying civilization of humanoid aliens, they are biologically comparable with terrestrial life forms on Earth, although adapted to the Martian gravity 0.38g. Mars is a desert world with a thin atmosphere, most of its water is gone, the current belief is that the water was absorbed by the crust as the planet became less geologically active, the water that remains is found in the planets ice caps and its system of canals which have been maintained by the Martians.
Up until the arrival of the first human expedition in 1984, Mars had a thriving but reclusive and inward looking civilization with an estimated population in the low billions, these Martians are largely peaceful and had no designs on Earth and mostly wanted to be left alone, unfortunately having long since conquered and eradicated all disease on their planet, they had no resistance to the diseased brought by the seven astronauts of the Ares 2 expedition.
These Martians had very powerful psionic capabilities capable of affecting a humans visual cortex and other sensory inputs. The first and second expeditions were killed, the first one landed a lone astronaut on the planet's surface, he landed in an isolated area, the Martians managed to contain the threat of contagion after killing him, with the second expedition, the Martians weren't so fortunate, this one landed four astronauts near a Martian city, three astronauts remained in the mothership, using psionic attacks the four astronauts were made to experience a familiar environment taken from their own memories, they were fed poison food and died, but it was too late for the Martians, the contagion already escaped and could not be contained killing off 99.999% of the Martian population while the remainder managed to develop resistance to human diseases, there are estimated to be a few hundred thousand Martians remaining, most live underground in caves, many have used their psionic powers to cloak their appearance as humans, and they have managed to hide among the humans themselves.
Martians try to avoid areas with high populations, as so many minds tends to overwhelm them.
Up until the arrival of the first human expedition in 1984, Mars had a thriving but reclusive and inward looking civilization with an estimated population in the low billions, these Martians are largely peaceful and had no designs on Earth and mostly wanted to be left alone, unfortunately having long since conquered and eradicated all disease on their planet, they had no resistance to the diseased brought by the seven astronauts of the Ares 2 expedition.
These Martians had very powerful psionic capabilities capable of affecting a humans visual cortex and other sensory inputs. The first and second expeditions were killed, the first one landed a lone astronaut on the planet's surface, he landed in an isolated area, the Martians managed to contain the threat of contagion after killing him, with the second expedition, the Martians weren't so fortunate, this one landed four astronauts near a Martian city, three astronauts remained in the mothership, using psionic attacks the four astronauts were made to experience a familiar environment taken from their own memories, they were fed poison food and died, but it was too late for the Martians, the contagion already escaped and could not be contained killing off 99.999% of the Martian population while the remainder managed to develop resistance to human diseases, there are estimated to be a few hundred thousand Martians remaining, most live underground in caves, many have used their psionic powers to cloak their appearance as humans, and they have managed to hide among the humans themselves.
Martians try to avoid areas with high populations, as so many minds tends to overwhelm them.