Albert Einstein publishes his special theory of relativity. Einstein is later honored with the Nobel Prize for his work.

Dr. Leonard McCoy in Earth's past, having gone through the Guardian of Forever while under influence of accidental overdose of cordrazine, causes major damage to the flow of history by preventing the death of social worker Edith Keeler. Kirk and Spock, on a mission to prevent this occurrence, are able to reverse the damage by permitting the death to occur. It is reported that failure to permit Keeler's death would have triggered a chain of events in which Nazi Germany was able to develop atomic weapons, resulting in Hitler's winning of World War II.

Seven women are knifed to death in Shanghai, China, on planet Earth The murders remain unsolved until 2267, when new information suggests they had been committed by an energy being that thrives on fear.

The first short story featuring fictional detective Dixon Hill is published in Amazing Detective Stories Magazine. Many years later, Enterprise captain Jean-Luc Picard becomes an avid fan of the Dixon Hill mysteries.

Another Dixon Hill detective story, "The Long Dark Tunnel" is published in Amazing Detective Stories Magazine.

The United Nations is chartered on planet Earth in the city of San Francisco. The organization represents a significant effort in the quest for planetary peace.

Sputnik I, Earth's first artificial satellite, is launched, marking the dawn of Earth's space age.

Yuri Gagarin, aboard space vehicle Vostok I, becomes first human to travel in space.

Earth-based radio telescopes are used to listen for evidence of radio signals from Tua Ceti and Epsilon Eridani as part of Project Ozma, one of Earth's first attempts to search for extraterrestrial life.

Nuclear Test Ban Treaty is adopted on planet Earth. The agreement represents a significant early step toward the control of nuclear weapons.

Scientists on Miri's planet begin a "life prolongation project," creating a virus intended to halt the aging process. The project is a terrible disaster and results in the death of all the adults on the planet. The planet's children survive, aging at a greatly reduced rate, although the virus causes their death upon the onset of puberty.

The U.S.S. Enterprise, on a historical research mission into the past, encounters Gary Seven, a human trained by unknown aliens, being returned to Earth to help that planet survive it's critical nuclear age. Kirk accidently interferes with this mission, but is able to restore events before a nuclear missile can cause a disastrous explosion.

The U.S.S. Enterprise, accidentally sent into the past by near collision with a black hole, is detected as an unidentified flying object in Earth's atmosphere. In attempting to prevent further detection, Kirk accidentally captures U.S. Air Force Captain John Christopher. Christopher is returned during th light-speed breakaway factor maneuver which also returns the Enterprise to it's own time.

July 20,1969. Neil Armstrong becomes first human to walk on Earth's moon. Dedication on landing ship Eagle proclaims: "We came in peace for all mankind."

Five women are brutally knifed to death in Kiev, USSR, on planet Earth. It is later discovered that these murders were probably committed by the same energy entity responsible for similar killings on planet Argelius in 2267.

Viking I space probe lands on Mars, Earth's first major attempt to employ space exploration in the search for extraterrestrial life.

First spaceship Enterprise (Space Shuttle OV-101) undergoes flight testing.

Shuttle Columbia, earth's first reusable spaceship, makes first orbital flight.

Pioneer 10 spacecraft becomes first human-launched space probe to leave Earth's solar system. The craft drifts in deep space until it is destroyed in 2287 by a Klingon Bird-of-Prey. Pioneer 10 had been launched from Earth on March 2, 1972.

Seven astronauts killed when spaceship Challenger explodes 73 seconds after liftoff.

Klingon Bird-Of-Prey piloted by Kirk and his crew land in old San Francisco to take two humpback whales back to the future. Using the ship's cloaking device, the vessel remains undetected by terrestrial authorities, although Commander Pavel Chekov is temporarily incarcerated by military authorities while working to repair the spacecraft. Cetacean biologist Gillian Taylor leaves this time period and travels to 23rd century with Kirk.

Dr. Nichols, a scientist and plant manager at Plexicorp in San Francisco, begins to develop the molecular matrix for transparent aluminum on his Macintosh computer.

The book Chicago Mobs of the Twenties is published in New York. A copy of this book is carried onboard the Federation starship U.S.S. Horizon in 2168, and is accidentally left on planet Sigma Iotia II in that year.

Khan Noonien Singh rises to power, assuming dictatorial control over one quarter of the planet Earth, from South Asia to the Middle East. Khan is the product of genetic engineering and eugenics experiments

A group of eugenically bred "superior" humans seize power simultaneously in some forty of Earth's nations. Terrible wars ensue, in part because the genetic "supermen" take to fighting aong themselves. Entire populations are bombed out of existence during these Eugenics Wars, and Earth is believed to be on the verge of a new dark age.

Claire Raymond, a woman living on Earth, dies of an embolism. Her husband Donald Raymond, has her cryogenically frozen and sent into space for possible revival at some future date. The satellite containing her body is eventually discovered in 2364 by the starship Enterprise.

Eugenics Wars over, Khan Noonien Singh is overthrown and escapes from Earth on the DY-100 class sleeper ship S.S. Botany Bay along with 96 of his fellow genetic "supermen."

Poet Tarbolde writes "Nightingale woman," a love sonnet considered to be among the most passionate for the next two centuries.

Voyager 6 spacecraft launched from Earth. This probe eventually fell into a black hole, emerging on the other side of the galaxy, where it encountered a planet of living machines that enhanced the craft and returned it to Earth in 2271.