Big events happen every year, but 2012 was packed with action. On June 5, sky watchers got a rare view of Venus moving across the sun, seen above. During the event, called the transit of Venus, a little black dot appeared to move slowly across the face of the sun. It won't happen again for 105 years!

This year also saw the world's top athletes come together to compete in the Summer Olympics, in London, England. Hurricane Sandy hit the U.S. in October. Cleanup and rebuilding efforts continue to this day. In November, after an exciting election season, U.S. voters elected President Barack Obama for a second term. It was a year with unforgettable highs, crushing lows and the everyday events that happen in between. As we look ahead to a new year, click through this slide show for a look back at a few of the most moving and memorable moments of 2012.

An Italian cruise ship called the Costa Concordia hit rocks on January 13 near the coast of Giglio, a small island in Italy. The impact tore a huge hole in the ship's hull. The 4,200 passengers and crew members had to abandon ship. More than 30 people died in the disaster.

New York Giants quarterback Eli Manning celebrates after his team beat the New England Patriots 21-17 in Super Bowl XLVI on February 5. Manning was named MVP of the NFL championship, which was played in Indianapolis, Indiana.

Thunderstorms and tornadoes swept through Alabama, Tennessee, Kentucky, Indiana and Ohio in early March. The twisters killed at least 38 people and damaged many homes, including this one in Holton, Indiana. These storms were part of an especially bad tornado season.

One World Trade Center rose to 1,271 feet--and 100 floors--on April 30, to become the tallest building in New York City. It beat the observation deck of the Empire State Building. The building will reach its full height of 1,776 feet in 2013.

SpaceX, a U.S. company, sent an unmanned supply ship called the Dragon to the International Space Station (ISS) on May 22. It was the first time a private company—instead of a government—made a delivery to the ISS.

Egyptian supporters of presidential candidate Mohamed Morsi celebrate after Morsi was declared the winner of the race on June 24. The vote took place 16 months after Egyptians forced Hosni Mubarak to step down as their leader. The elections were part of a series of big changes across the Middle East and North Africa.

U.S. swimmer Michael Phelps won a record 19th Olympic medal at the Summer Games in London, England, on July 31. The win made him the most decorated Olympian of all time. Phelps retired from competitive swimming after the Games. He ended his career with a total of 22 Olympic medals.

Click here for more images from the 2012 Summer Games.

Mitt Romney greets supporters at the Republican National Convention, in Tampa, Florida. Republicans officially nominated the former governor of Massachusetts for President during the convention. Romney's running mate, Wisconsin congressman Paul Ryan, was nominated for Vice President.

Around 350,000 students returned to their classrooms on September 19 after teachers ended a seven-day school strike in Chicago, Illinois. It was the first teachers' strike in Chicago in 25 years. Chicago is one of the largest school districts in the nation.

In October, Hurricane Sandy brought strong winds, rain and flooding to the East Coast, including parts of New York City and New Jersey. The storm was the second-most-expensive hurricane ever to strike the U.S. It left millions of people in need. Here, a man views damage in the Rockaway neighborhood of New York's Queens borough.

Voters reelected President Barack Obama on November 6. He won a second term in the nation's top office. Obama beat Republican Mitt Romney in a tough race. The popular vote was nearly split down the middle. Here, Obama celebrates with First Lady Michelle Obama, Vice President Joe Biden and Jill Biden.

On December 6, the White House released its 2012 holiday card, painted by Iowa artist Larassa Kabel. The black-and-white illustration features Bo, the Obama family's Portuguese water dog, walking in snow in front of the White House. Bark! Happy holidays!