There are no aliens on the moon, but that might not stop it from trying to kill us.
Lunar soil is exposed to micrometeorite impacts and because the moon lacks an atmosphere, constant intense solar wind. As a result, the soil is electrostatically charged, so much so that it can levitate above the surface of the moon.
This dust was a problem faced by the Apollo astronauts. It stuck to their suits, following them into their spaceship, coagulating in vents and causing “lunar hay fever” in astronaut Harrison Schmitt.
Lunar dust is problematic because of its intense static charge, but also because of its size. Small particles (5-10 mcg) can accumulate in airways, smaller particles (0.5-5 mcg) can travel right into lung alveoli, and at least in rats, the smallest of particles (<0.1 mcg) can travel through the olfactory bulb right into the brain.
A study has recently shown that human neuron and lung cells exposed to simulated lunar dust experienced DNA damage and cell death, even in very small quantities.
This isn’t totally unexpected. Earth dust can have similar effects, toxic or not. Volcanic ash has been known to cause bronchitis and emphysema when inhaled. But the degree to which lunar dust damaged cells was unexpected. The scientists were at times unable to measure the extent of DNA damage since it was completely destroyed.