Instructions
Buy the Farstar e3 telescope for $2,100. A cheaper telescope, the Astrowonder, is available for $550, but Sims who use it never get abducted by aliens.
Direct a Sim to the telescope between the hours of 7 p.m. and 2 a.m. Let the Sim stargaze all night. At random, an alien spaceship grabs the Sim and carries him into the sky.
Wait for the abducted Sim to return home. This usually takes two or three days. When the Sim returns, listen for a short melody. The melody means that the abducted Sim is now pregnant.
Watch the Sim during the next three days. The day after the Sim returns home, she has morning sickness. Her stomach grows bigger each day. On the third day, the Sim gives birth to an alien baby with pale green skin and black eyes.