The Mars Exploration Rover Spirit lands on the Red Planet on January 3, 2004. 21 days later, its twin, Opportunity, also arrived safely. In one of the longest and most successful missions in NASA history, Spirit would survey Martian geography for the next seven years, while Opportunity remained active until June of 2018.

At an energetic rally on the evening of January 19, 2004, Democratic presidential hopeful Howard Dean emits a noise that many will claim ended his career in electoral politics. The “Dean Scream,” as it quickly came to be known, was a unique and revealing moment in early-21st century American politics.

A singularly sensational event occurs during the halftime show of the Super Bowl on February 1, 2004. While performing a duet with Janet Jackson, Justin Timberlake briefly exposed one of her breasts in what was later described as a "wardrobe malfunction."

On February 4, 2004, a Harvard sophomore named Mark Zuckerberg launches The Facebook, a social media website he had built in order to connect Harvard students with one another. By the next day, over a thousand people had registered, and that was only the beginning. Now known simply as Facebook, the site quickly ballooned into one of the most significant social media companies in history. Today, Facebook is one of the most valuable companies in the world, with over 2 billion monthly active users.

The Passion of the Christ, Mel Gibson’s controversial film about the last 44 hours of Jesus of Nazareth’s life, opens in theaters across the United States on February 25, 2004. Not coincidentally, the day was Ash Wednesday, the start of Lent for many Christian denominations.

On March 4, 2004, Mianne Bagger, a golfer from Denmark, makes history at the Women’s Australian Open as the first transgender athlete to compete in a professional golf tournament. Bagger shoots an underwhelming 84 (12 over par) in her first round, but that is a footnote to the historic performance.

On March 11, 2004, 193 people are killed and nearly 2,000 are injured when 10 bombs explode on four trains in three Madrid-area train stations during a busy morning rush hour. The bombs were later found to have been detonated by mobile phones. The attacks, the deadliest against civilians on European soil since the 1988 Lockerbie airplane bombing, were initially suspected to be the work of the Basque separatist militant group ETA. This was soon proved incorrect as evidence mounted against an extreme Islamist militant group loosely tied to, but thought to be working in the name of, al-Qaida.

On April 11, 2004, Phil Mickelson wins the Masters Golf Tournament at Augusta National Golf Club, his first major championship in nearly 12 years as a professional golfer.

Pat Tillman, who gave up his pro football career to enlist in the U.S. Army after the terrorist attacks of September 11, is killed by friendly fire while serving in Afghanistan on April 22, 2004. The news that Tillman, age 27, was mistakenly gunned down by his fellow Rangers, rather than enemy forces, was initially covered up by the U.S. military.

On April 28, 2004, the CBS program 60 Minutes II reports on abuse of prisoners by American military forces at Abu Ghraib, a prison in Iraq. The report, which featured graphic photographs showing U.S. military personnel torturing and abusing prisoners, shocked the American public and greatly tarnished the Bush Administration and its war in Iraq.

On April 29, 2004, the World War II Memorial opens in Washington, D.C. to thousands of visitors, providing overdue recognition for the 16 million U.S. men and women who served in the war. The memorial is located on 7.4 acres on the former site of the Rainbow Pool at the National Mall between the Washington Monument and the Lincoln Memorial. The Capitol dome is seen to the east, and Arlington Cemetery is just across the Potomac River to the west.

On April 29, 2004, the last Oldsmobile comes off the assembly line at the Lansing Car Assembly plant in Michigan, signaling the end of the 106-year-old automotive brand, America’s oldest. Factory workers signed the last Oldsmobile, an Alero sedan, before the vehicle was moved to Lansing’s R.E. Olds Transportation Museum, where it went on display. The last 500 Aleros ever manufactured featured “Final 500″ emblems and were painted dark metallic cherry red.

On May 5, 2004, a suitcase holding what is later identified as the partial remains of William McGuire, a 39-year-old Navy veteran and computer analyst is pulled from the water near Virginia Beach. A second suitcase of body parts was found nearby on May 11, and a third washed up near the Chesapeake Bay Bridge and Tunnel on May 15.

At 9:00 p.m. Eastern and Pacific times on May 6, 2004, that familiar theme song (“I’ll Be There For You” by the Rembrandts) announces the beginning of the end, as an estimated 51.1 million people tune in for the final original episode of NBC’s long-running comedy series Friends.

On May 7, 2004, marine biologist Richard Thompson publishes an article in the journal Science detailing the troubling amount of microscopic plastic fragments and fibers that he and his team have discovered in the world’s oceans and marine habitats. Thompson dubs the debris “microplastics” and questions whether these particles could release harmful chemicals and pose a danger to the environment.

Marcia Kadish, 56, and Tanya McCloskey, 52, of Malden, Massachusetts, marry at Cambridge City Hall in Massachusetts, becoming the first legally married same-sex partners in the United States. Over the course of the day, 77 other same-sex couples tied the knot across the state, and hundreds more applied for marriage licenses. The day was characterized by much celebration and only a few of the expected protests materialized.

On May 22, 2004, President George Bush is in a bicycle accident. Bush had taken up mountain biking for exercise at the suggestion of physicians.

On May 22, 2004, Michael Moore’s documentary film Fahrenheit 9/11 beats out 18 other films to win the coveted Palme d’Or, the top prize at the Cannes Film Festival. It became the first documentary to triumph at Cannes since The Silent World, co-directed by Jacques Cousteau and Louis Malle, won the Palme d’Or in 1956.

On June 1, 2004, opening statements begin in the trial of Scott Peterson, accused of murdering his wife Laci and the couple’s unborn son. On Christmas Eve 2002, the pregnant Laci had disappeared from Modesto, California. The case captivated millions across America and saturated national media coverage for nearly two years.

On June 5, 2004, Ronald Wilson Reagan, the 40th president of the United States, dies after a long struggle with Alzheimer’s disease. Reagan, who was also a well-known actor and served as governor of California, was a popular president known for restoring American confidence after the problems of the 1970s.

On June 5, 2004, some 40 guests watch as the pop star and actress Jennifer Lopez weds her third husband, the singer Marc Anthony, in an intimate ceremony held in the backyard of Lopez’s home in Los Angeles.

On June 21, 2004, SpaceShipOne becomes the first privately owned spacecraft to reach an altitude of 100 kilometers, or about 62 miles, above the earth, the generally accepted point at which “space” begins.

On August 21, 2004, American swimmer Michael Phelps wins his eighth medal of the 2004 Athens Olympics in spite of sitting out his eighth scheduled event, the final of the 4 x 100-meter medley relay. Phelps left Athens with six gold and two bronze medals. His eight total medals tied him with Soviet gymnast Aleksandr Dityatin for the most medals ever won by a competitor at a single Olympic Games.

On August 29, 2004, Brazilian distance runner Vanderlei de Lima is attacked by a spectator while running the marathon, the final event of the Summer Olympics in Athens, Greece. At the time of the incident, De Lima had a 30-second lead in the race with four miles to go.

On September 1, 2004, an armed gang of Chechen separatist rebels enters a school in southern Russia and takes more than 1,000 people hostage. The rebels demanded the withdrawal of Russian troops from the disputed nearby region of Chechnya. September 1 was the first day of a new school year for millions of students across Russia, a day of celebration in schools that both parents and students traditionally attend. Nearly 340 people, about half of them children, died in the ensuing three-day ordeal.

A three-day hostage crisis at a Russian school comes to a violent conclusion after a gun battle erupts between the hostage-takers and Russian security forces. In the end, over 300 people died, many of them children, while hundreds more were injured.

On September 12, 2004, the first season of the television comedy series "Entourage_,_" about a hot young actor in Hollywood and the posse of people surrounding him, comes to an end on HBO. "Entourage," which debuted on July 18, 2004, starred Adrian Grenier as the up-and-coming movie heartthrob Vincent Chase, who is navigating his way through the pitfalls and excesses of Hollywood.

On September 13, 2004, TV talk-show host Oprah Winfrey gives a brand-new Pontiac G-6 sedan, worth $28,500, to everyone in her studio audience: a total of 276 cars in all.) Oprah had told her producers to fill the crowd with people who “desperately needed” the cars, and when she announced the prize (by jumping up and down, waving a giant keyring and yelling “Everybody gets a car! Everybody gets a car!”), mayhem–crying, screaming, delirium, fainting–broke out all around her. It was, as one media expert told a reporter, “one of the great promotional stunts in the history of television.”

On October 8, 2004, Kenyan environmental justice organizer Wangari Maathai receives a Nobel Peace Prize in recognition of her “contribution to sustainable development, democracy and peace," becoming the first African woman to win the award.

On October 10, 2004, the actor Christopher Reeve, who became famous for his starring role in four Superman films, dies from heart failure at the age of 52 at a hospital near his home in Westchester County, New York. Reeve, who was paralyzed in a 1995 horse-riding accident, was a leading advocate for spinal cord research.

On October 15, 2004, the National Highway Traffic Safety Administration rules that hearse manufacturers no longer have to install anchors for child-safety seats in their vehicles. In 1999, to prevent parents from incorrectly installing the seats using only their cars’ seat belts, the agency had required all carmakers to put the standardized anchors on every passenger seat in every vehicle they built. Though it seemed rather odd, most hearse-builders complied with the rule and many thousands of their vehicles incorporated baby-seat latches on their front and back passenger seats.

On October 27, 2004, the Boston Red Sox win the World Series for the first time since 1918, finally vanquishing the so-called “Curse of the Bambino” that had plagued them for 86 years. “This is for anyone who has ever rooted for the Red Sox,” Boston general manager Theo Epstein tells reporters. “This is for all of Red Sox Nation, past and present.”

On November 9, 2004, Swedish writer Stieg Larsson dies suddenly of a heart attack at age 50, only months after turning in the manuscripts for three crime thrillers—“The Girl with the Dragon Tattoo,” “The Girl who Played with Fire” and “The Girl who Kicked the Hornet’s Nest”—which would later become international best-sellers. Known collectively as the Millennium trilogy, the novels feature the characters Mikael Blomkvist, a middle-aged journalist, and Lisbeth Salander, a young pierced and tattooed computer hacker with a troubled past. Larsson, who never lived to see his books’ success, died without a will, setting off a protracted legal battle for the rights to his work.

On November 12, 2004, Scott Peterson is convicted of murdering his wife Laci and their unborn son. A jury of six men and six women delivered the verdict 23 months after Laci Peterson, who was pregnant, disappeared on Christmas Eve from Modesto, California. The case captivated millions across America and saturated national media coverage for almost two years.

On November 19, 2004, Metta Sandiford-Artest (then known as Ron Artest) of the Indiana Pacers jumps into the stands to confront a Detroit Pistons fan who throws a drink at him as he rests on the scorers' table. This ignites what becomes known as "Malice at the Palace," one of the more infamous moments in sports history.

On November 30, 2004, after winning 74 straight games and more than $2.5 million—a record for U.S. game shows—Jeopardy! contestant Ken Jennings loses. Jennings’ extended winning streak gave the game show a huge ratings boost and turned the software engineer from Salt Lake City, Utah into a TV hero and household name. Barbara Walters named him one of the 10 most fascinating people of the year and Jennings appeared on such shows as Late Night with David Letterman, The Tonight Show with Jay Leno and even Sesame Street.

A powerful earthquake off the coast of Sumatra, Indonesia, on December 26, 2004 sets off a tsunami that wreaks death and devastation across the Indian Ocean coastline. The quake was the second strongest ever recorded and the estimated 230,000 dead made this disaster one of the 10 worst of all time.