Pope Benedict XVI is back in Rome following his week-long-travels to Mexico and Cuba. In reviewing almost 4,000 images that documented his historic travels to the two countries, I decided to concentrate on Cuba, a country that because of travel restrictions, still remains a bit of a mystery to most of us. The first image, though, shows the Pope traveling to Cristo Rey sanctuary in Mexico to lead the holy mass celebration. The Pope urged the faithful to seek a humble and pure heart and trust in God in the face of evil. While in Cuba, in the heart of Revolution Square, with the towering images of guerrilla heroes staring back at him, the Pope called for "authentic freedom" in one of the world's most authoritarian states. Benedict's visit comes 14 years after the historic first papal trip to Cuba by Pope John Paul II, a visit that yielded an era of greater religious expression. – Paula Nelson (50 photos total)

Syrians by the thousands are fleeing the violence in their home country and seeking refuge in neighboring countries. Turkey this week is said to be considering a buffer zone in Syria to secure its own national security as well as aid fleeing civilians. Turkey is already sheltering some 17,000 of those who have fled. The British-based Syrian Observatory for Human Rights said Tuesday that nearly 10,000 people have been killed in the yearlong conflict in Syria. A cease-fire agreement accepted by Syria Tuesday that was drawn up by United Nations envoy Kofi Annan was met with skepticism, and fighting continued between rebels and President Bashar Assad’s soldiers. -- Lloyd Young (32 photos total)

Is the recent political thaw in Myanmar genuine? Democratic elections are coming to the long-reclusive southeast Asian nation of Myanmar, formerly Burma. A long military dictatorship has nominally ended, and the regime has signed peace treaties with several ethnic separatist insurgencies. Nobel laureate Aung San Suu Kyi's long house arrest is over, and she is campaigning for a seat in Parliament in the upcoming April 1 vote. Western investment is beginning to mass, which may ultimately be the reason the country is finally opening its doors. Other speculation on the thaw points to the incompetent emergency response to Cyclone Nargis in 2008, which left as many as 140,000 dead and sowed deep dissatisfaction with the government. Whatever the reasons for the unprecedented opening, the isolated and impoverished Burmese people are eager to reconnect with and catch their more developed neighbors in ASEAN, the Association of South East Asian Nations. While it's impossible to represent every corner of any nation, collected here are images from the last couple of months in Myanmar, a nation of 55 million. -- Lane Turner (41 photos total)

Purim, one of the most joyous holidays in the Jewish calendar was held a week ago, March 8 and 9, celebrating the deliverance of the Jewish people in exile in Persia. The story is told in the Book of Esther, which is read as part of the holiday, remembering how a young Jewish girl became queen of Persia and risked the anger of her new husband to get him to prevent an attack on all Jews living in Persia, men, women, and children. The story, also called the Megillah, tells of the fall of the king’s feared adviser, who perishes out of his own malice, the bravery of a young woman, and the perseverance of the Jewish people. The festival is celebrated with gifts of food and drink, feasting, and games, especially dressing in costumes to remember how Esther was chosen as most beautiful in the kingdom. -- Lloyd Young (22 photos total)

Seemingly strange weather patterns continue to break high and low temperature records. The same patterns spawned an early tornado season in the midwestern United States and brought late season snowstorms to the west. Record snow falls and frigid temperatures characterized a particularly difficult winter across Europe with many deaths attributed to the conditions. Signs of Spring for the Northern Hemisphere (which began officially with the Vernal Equinox - March 20 - when the hours of day are approximately equal to the hours of night) like trees blossoming and flowers blooming, the shedding of winter coats and the desire of anyone -who has spent an all too long winter season indoors - to venture outside to soak up the sun. -- Paula Nelson (45 photos total)

World Water Day is observed on March 22 every year. The day to recognize the importance of earth's most precious natural resource was proposed 20 years ago at the United Nations Conference on Environment and Development. While we often take water for granted, many cannot. And water plays a role in almost everything we do. We drink it, wash in it, play in it, generate power with it, irrigate crops with it, travel and transport goods on it, fight fires with it, and worship with it. Gathered here are images of water from the last year in all its uses, in scarcity and in abundance. -- Lane Turner (48 photos total)

The 40th Iditarod Trail Sled Dog Race came to an end earlier this week in Nome, Alaska. Dallas Seavey, 25, bested both his father and his grandfather with his team of nine dogs, becoming the youngest musher ever to win the nearly 1,000-mile race across the Alaskan wilderness. His winnings included $50,000 and a new truck. Gathered here are images from the Iditarod and other events from around the globe.(29 photos total)

Angry protests broke out and shock rippled through Afghanistan on February 21 when accounts surfaced that NATO personnel at Bagram Air Base had burned a number of Korans and were preparing to burn more. A NATO spokesman said the books were inadvertently sent for incineration after being gathered at a detention facility for suspected insurgents. The incident brought nearly a week of strong anti-American demonstrations in which 30 people, including American troops were killed and many others wounded. Despite President Obama's letter of apology to President Hamid Karzai, the violence escalated. Two American soldiers were shot dead inside the Interior Ministry building in Kabul on Feb. 25. On Feb. 27, two suicide attackers detonated a car bomb at the entrance to a NATO air base in eastern Afghanistan. The Taliban claimed responsibility for the bombing as revenge for the burning of the Korans. While the violence raged, Afghan civilians faced harsher than usual winter weather and cold temperatures in which more than 40 people, mostly children, have frozen to death. -- Paula Nelson (48 photos total)

Mourning the loss of almost 20,000 people gripped Japan yesterday on the anniversary of the March 11, 2011 earthquake, tsunami and nuclear disaster. While the nation has made enormous strides recovering from the triple disaster, yesterday was was a time for remembrance. But the country is rebuilding even as it still suffers the loss of lives and the economic effects of an estimated $210 billion price tag - the costliest natural disaster in human history. Gathered here are images from memorial services, the rebuilding efforts, and of people forging ahead with altered lives a year on from the catastrophe. -- Lane Turner (40 photos total)

Photographer Phyllis B. Dooney is documenting the plight of Japan's evacuees who fled the nuclear disaster in Fukushima prefecture after the March 11, 2011 earthquake and tsunami. She writes,"In Fukushima Prefecture, the third and most permanent disaster in the series followed; a nuclear meltdown occurred at Tokyo Electric’s Fukushima Daiichi plant. Radiation poured into the atmosphere and environment. First it was a suggestion, but by mid-April the government was enforcing the mandate that the residents of Tomioka and Kawauchi, who hadn’t already left because of the earthquake and/or tsunami damage, leave indefinitely.  Nearly one year later an estimated 80,000 nuclear refugees are living in government-issued temporary housing or elsewhere. In the temporary housing, often just outside the evacuation zone, it is the elderly and mentally or physically disabled who comprise a large percentage of the residents." Collected here are images of those evacuees made by Dooney in August of last year and in the last few days. -- Lane Turner (25 photos total)

In this first of three Big Picture posts on the anniversary of the Japan earthquake-tsunami-nuclear disaster, we have a series of paired "then and now" pictures, with the first image taken recently paired with a picture from the same vantage point taken during or in the immediate aftermath of the tragedy. CLICK ON IMAGES 2 THROUGH 27 TO SEE THE SAME AREA ONE YEAR AGO. This effect requires javascript to be enabled. Outside of Japan's nuclear exclusion zone the country has made a remarkable cleanup of the areas ravaged by the March 11, 2011 earthquake and tsunami. But a quasi-normality reigns, with some formerly devastated areas now orderly, yet not as they were before the tragedy, while other areas bear heavy signs of damage. Several photographers recently painstakingly recreated scenes photographed during the original events. AFP's Toru Yamanaka said the task was very difficult, with many of the visual clues wiped away. Yamanaka said he had to ask local residents where they thought the original photos were taken. In Ishinomaki, he walked into the city hall and showed people a photograph of a piece of land with many stones scattered on it. "All the city officials from one section came out and tried to help me. They stared at the picture all together but still couldn't figure it out. One young woman, also working at the city hall, then shouted: 'I got it!' She pointed out a tiny building in the background that was under construction, and said, 'I know the building.'" The last three images, as well as the first image here, are of Yuko Sugimoto and her son, Raito. Photographed wrapped in a blanket looking for her son, the moment became an iconic image of the disaster. Thankfully, their story has a happy ending, as the pair were safely reunited. -- Lane Turner (56 photos total)

The Smithsonian magazine's 9th annual photo contest finalists have been chosen. The contest attracted over 14 thousand photographers from all 50 states and over 100 countries. Fifty finalists from 67,059 images were selected by Smithsonian editors. Those editors will also choose the Grand Prize Winner and the winners in each of the five categories which include The Natural World, Americana, People, Travel and Altered Images. Photos were selected based on technical quality, clarity and composition, a flair for the unexpected and the ability to capture a picture-perfect moment. (Smithsonian invites everyone to select an additional "Readers' Choice" winner by voting through March for their favorite image on line.) -- Paula Nelson (25 photos total)

Traditionally a rite that celebrates the coming of spring, Holi is marked by joyous participants throwing colored water and powder. In northern Uttar Pradesh, "Lathmar Holi" is celebrated before Holi itself, and while it is a rite of spring there as well, the festival also features another layer of fun rooted in Hindu mythology. Lord Krishna is said to have visited the village of Barsana to tease his consort Radha. Women in the town responded by chasing him away. Today women from Barsana "beat" the men from Krishna's village of Nandgaon with sticks for singing provocative songs and throwing colored powder on them. This year Holi itself will be celebrated throughout India and in other places on March 8. -- Lane Turner (22 photos total)

Weather predictions for possible tornadoes from a new storm system today threaten the Midwest and South, and have recent victims nervous about what the day might hold. The first powerful storm system tore through parts of the Midwest and South earlier this week, killing 13 people from Kansas to Kentucky, leaving pockets of devastation across several states and marking the acceleration of another deadly (and early) tornado season. Tornadoes and powerful winds tore off roofs, leveled homes and businesses, tossed mobile homes, downed power lines and injured more than 150 people. The damage was most significant in Harrisburg, a small town in southern Illinois where blocks of houses and businesses were reduced to rubble. -- Paula Nelson(25 photos total)