Asterite

Asterites is an unofficial designation given to an intelligent species of strange, fairy-like beings which originally inhabited the fifth planet of the Sol System, before their world was destroyed by the Martians and its remains formed what is now known as the asteroid belt.

Contrary to the Martians' expectations, the Asterites survived the destruction of their planet by encysting themselves into a gem-like state of suspended animation. It is believed that they were later responsible for wiping out the Martian civilization.

Biology
The Asterites are peculiar creatures with peculiar abilities. Their winged bodies have been described as shimmery and moth-like, and they resemble the typical image of a fairy. Fittingly, they can also turn themselves invisible, at least to Human senses.

They can also encyst themselves, assuming a gem-like appearance which is extremely durable, as it has enabled them to survive the annihilation of their planet and become scattered across numerous asteroids. Although the gems can be destroyed in laboratory, their composition cannot be analyzed by chemical means. Certain musical notes are required to awaken the Asterites from their encysted state.

The Asterites are most notable for exerting a soothing and mind-altering effect in the minds of other beings, encircling them in an atmosphere of peace which can cure stress and even insanity, but which leaves the individual with a completely altered personality, to the point that little to nothing remains of their original selves. For this reason the ancient Martians feared the Asterites and attempted to exterminate them.

Appearances

 * "Hunch", by Clifford D. Simak (1943)