Deimos is the smaller "moon" of Mars. It is only about 8 miles in diameter, and less than a millionth of the mass of Earth's moon.
The drawing that Cortazar makes on the window resembles the structure of an RNA strand with the base-pairing and various loops and hairpin bends.
The scientist with brain damage (and a lack of empathy) who was part of the Eros experiment was compared to a pedophile, and Eros was his pedophilia. The word choice is ironic, since the name of the asteroid (Eros) is the Greek god of sexual love and desire.