The appearance of Halley's Comet in 1986 was a highly heralded phenomenon causing people to organize observations of its passage. The relative positions of the Earth and the comet, however, would cause a less than favorable sighting. Nevertheless, in 1986, the Giotto space mission managed to probe directly into the comet and photograph its core. Halley returns every seventy-six years, and its nucleus releases ice and rocks into space. That residue becomes part of Halley's tail and leaves an orbiting trace that, upon falling to earth, is referred to as the Orionids meteor shower. 

Venezuelan astronomer Humberto Campíns declared that "the apparition of Halley's comet in 1986 was much less brilliant than in 1910, and this is due in part to pollution and night lights, but the passage in 1910 was extraordinarily good."

Halley's Comet was the first comet to be recognized as periodic; its orbit was first calculated by astronomer Edmund Halley in 1705. According to experts, data analysis shows that it was first sighted in the year 239 BC.  Certain religious groups believe that the comet is the star that marked the path toward the manger of Jesus.

That year, the government signed an agreement with The Chase Manhattan Bank and other international banks to restructure Venezuela's debt. In May, at the Yumare village in the state of Yaracuy, a political police commando led by captain Henry López Sisco seized, tortured and killed nine people.

On January 18, an airplane crash in Guatemala claimed the lives of Venezuelan politician Arístides Calvani, his wife Adela Abbo Fontana and their daughters Graciela and Elena.

Two tragedies shocked the world. On January 28, only 73 seconds after liftoff, space shuttle Challenger, along with its seven crewmembers, abruptly became a ball of fire as part of the two million liters of fuel exploded. Aboard was school teacher Christa McAuliffe, the first civilian to attempt to travel into space.

Months later a human error caused the worst nuclear accident in history. On April 26, during a test simulating a shutdown of the plant's power supply, a sudden rise in power in reactor 4 of the nuclear plant of Chernobyl overheated the nuclear reactor, which led to an explosion of the hydrogen stored in its interior. The quantity of radioactive material released was considered 500 times greater than that released by the atomic bomb dropped on Hiroshima in 1945.

But this year would also generate hope. The Public Health Service of the United States approved AZT (zidovudine) for treatment of HIV positive patients.