Police in tactical gear arrive on an armored police vehicle to surround an apartment building in search for a suspect in the Boston Marathon bombings in Watertown, Mass., Friday, April 19.
Astronomers have used NASA's Hubble Space Telescope to photograph the iconic Horsehead Nebula in a new, infrared light in this NASA image of the day for April 19, to mark the 23rd anniversary of the famous observatory's launch aboard the space shuttle Discovery on April 24, 1990.
This Thursday, April 18, aerial photo shows the remains of a nursing home, left, apartment complex, center, and fertilizer plant, right, destroyed by an explosion in West, Texas.
Astronaut Chris Hadfield tweeted this photo of ice swirls off North Japan's coast from the International Space Station on April 19. He wrote, "Psychedelic ice swirls off the North Japan coast. pic.twitter.com/dzfdZBTOeF"
Eric the newborn Rothschild giraffe stands in front its mother Lotti during its first presentation for public at the Tierpark zoo in Berlin, Friday, April 19.
Astronaut Chris Hadfield tweeted this photo of sinkholes in Florida from the International Space Station on April 19. He wrote, "Yes, Florida has sinkholes. pic.twitter.com/S6dHq0PYAm"
Astronaut Chris Hadfield tweeted this photo of Amman, Jordan, from the International Space Station on April 19. He wrote, "Amman, capital of Jordan. The street pattern shows it as one of the oldest cities in the world. pic.twitter.com/J4aY9uPmXJ"
A dancer from the "Octopus," directed by award-winning choreographer Philippe Decoufle, performs during a technical rehearsal on Friday, April 19, at the Esplanade's theater on the bay in Singapore.
Astronaut Chris Hadfield tweeted this photo of the moonrise from the International Space Station on April 19. He wrote, "Tonight's Finale: Catching the Moon rising takes patience, but is worth it. pic.twitter.com/VJdfNTm5n3"
Dust plumes blow over parts of Arizona, New Mexico, Colorado, and Utah on April 16. The dust plumes arose in two large clusters, one in northeastern Arizona, and the other in northwestern New Mexico and grew in size and intensity through the day. The U.S. Drought Monitor reported that, with the exception of a small region in central Arizona, abnormally dry or drought conditions prevail throughout Arizona, New Mexico, Colorado, and Utah, with an area of extreme drought stretching across the Arizona-New Mexico border. Many of the dust plumes visible in these images arose in or near that area of extreme drought.
In August 2011, Canada's CN Tower was repeatedly struck by lightning during a 30-minute thunderstorm. Photographer Richard Gottardo captured this shot using a 20- to 30-second exposure.
A lightning bolt appears to strike the Eiffel Tower in this shot of the iconic Parisian landmark taken in July 2012.
A lightning bolt strikes near the Luxor Hotel and Casino in Las Vegas, Nev., on July 17, 2006.
Lightning strikes St Peter's dome at the Vatican on Feb. 11, 2013, the day Pope Benedict XVI announced he would soon resign as leader of the world's 1.1 billion Catholics.
A lightning bolt strikes the Empire State Building in New York City in 1957.
Lightning strikes over Stonehenge in Wiltshire, England.
Lightning strikes the 623-foot-high Turning Torso building in Malmo, Sweden, on June 7, 2011.
A bolt of lightning hits the Statue of Liberty on Sept. 22, 2010, in New York.
Lightning strikes behind the Washington Monument during a summer thunderstorm in August 2003.
Lightning strikes the top of the International Finance Centre in Hong Kong on Aug. 28, 2010. On that day, the Hong Kong Observatory recorded 1,913 cloud-to-ground lightning strikes over a period of two hours.
Tension was high as the search for a second Boston Marathon bombing suspect just about shut down Boston for much of Friday, April 19, 2013. Late in the day, authorities lifted their request that citizens stay indoors.
Summer Street in South Boston was vacant of cars at 9:30 a.m.
A lone pedestrian walks along Pearl Street in downtown Boston Friday, April 19, 2013.
This was the scene on Federal Street in the Financial District at around 3:20 p.m. during the ongoing manhunt for a suspect in the terrorist bombing.
Scenes from around Kendall Square as a manhunt was underway for a suspect in the terrorist bombing of the 117th Boston Marathon earlier this week.
A lone bicycle rider pedals across the Longfellow Bridge to Boston from Cambridge while the Boston Area was under lockdown.
A village woman reacts after her house was damaged by an earthquake in Lushan county, Ya'an, southwest China's Sichuan province on Saturday, April 20, 2013. The powerful earthquake struck the steep hills of China's southwestern Sichuan province Saturday, nearly five years after a devastating quake wreaked widespread damage across the region.
A Bahraini anti-government protester holds a poster opposing the upcoming Formula One Bahrain Grand Prix, to be held Sunday, next to a fire set by anti-government protesters during clashes with riot police firing tear gas in Qadam, Bahrain, on Friday, April 19, 2013. Clashes between protesters and police continued in Bahrain on Friday, ahead of Sunday's Formula One Grand Prix. Hardline protesters hope to embarrass the ruling royal family with increased violence, while more moderate protesters, who support the race, merely want to highlight their demands for a greater voice in the country.
Astronaut Chris Hadfield tweeted this photo from the International Space Station, writing, "Tonight's Finale: Newfoundland glowing on a lovely Spring evening. pic.twitter.com/Ty88Iiq9W9"
A police officer and a woman react to news of the arrest of one of the Boston Marathon bombing suspects, Friday, April 19, 2013, in Boston. Boston Marathon bombing suspect Dzhokhar Tsarnaev was captured in Watertown, Mass. The 19-year-old college student wanted in the bombings was taken into custody Friday evening after a manhunt that left the city virtually paralyzed and his older brother and accomplice dead.
A supporter of Venezuela's newly sworn-in President Nicolas Maduro holds a picture of late President Hugo Chavez during Maduro's inauguration in Caracas, Venezuela, Friday, April 19, 2013. The crowds were smaller and more subdued than those that turned out for Chavez, and the opposition boycotted Maduro's swearing-in, hoping that the ruling party's last-minute decision to allow an audit of nearly half the vote could change the result in the bitterly disputed presidential election.
Sea foam is seen amongst dead mangrove, formerly dense, green and a nesting sight for brown pelicans, egrets and roaseate spoon bill, which was directly impacted by oil from the Deepwater Horizon oil spill, is seen as it erodes into Barataria Bay at Cat Island in Plaquemines Parish, La., Thursday, April 18, 2013. Underneath the surface, environmentalists and scientists fear there may be trouble, from tiny organisms to dolphins. Yet the long-term environmental impact from the spill is still not fully known and will likely be debated for years to come.
Astronaut Chris Hadfield tweeted this photo from the International Space Station, writing, "Roman Yurievich Romanenko, outside in the universe for the very 1st time. A wondrous experience. pic.twitter.com/Q7vfcCa10f"
Isaac Brock of Modest Mouse performs at the 2nd weekend of the 2013 Coachella Valley Music and Arts Festival at the Empire Polo Club on Friday, April 19, 2013 in Indio, Calif.
Astronaut Chris Hadfield tweeted this photo from the International Space Station, writing, "A shoehorned band of development at the north end of Miami, between nature and the sea. pic.twitter.com/1UnWS4bEtW"
Philadelphia Phillies center fielder Ben Revere dives for a fly-out by St. Louis Cardinals' Pete Kozma during the sixth inning of a baseball game on Friday, April 19, 2013, in Philadelphia.
Indian policemen try to remove protestors shouting slogans outside Prime Minister's residence during a protest against the rape of a 5-year-old girl in New Delhi, India, Sunday, April 21, 2013. The girl was raped and tortured by a man who held her in a locked room in India's capital for more than two days.
The Boston Red Sox line up during a tribute to victims of the Boston Marathon bombing and its aftermath, as an image of Massachusetts Institute of Technology Police Officer Sean Collier is displayed on the scoreboard, before a baseball game against the Kansas City Royals in Boston, Saturday, April 20, 2013.
Astronaut Chris Hadfield tweeted this photo from the International Space Station, writing, "The Australian Outback is effortlessly crazily beautiful. pic.twitter.com/wspJub04WF"
Sunderland's Alfred N'Diaye, left, vies for the ball with Everton's Maroune Fellaini, right, during their English Premier League soccer match at the Stadium of Light, Sunderland, England, Saturday, April 20, 2013.
An elderly woman eats a meal near rubbish piled up at a refugee centre in the county seat of Lushan in southwestern China's Sichuan province, Sunday, April 21, 2013. Residents awoke Sunday after spending the night outdoors or in their cars in a town near the epicenter of a powerful earthquake that struck the steep hills of China's southwestern Sichuan province, leaving at least 160 people dead and more than 6,700 injured.
Benson Henderson, left, punches Gilbert Melendez during the third round of a UFC lightweight championship mixed martial arts fight in San Jose, Calif., Saturday, April 20, 2013. Henderson won by split decision to retain the championship.
Astronaut Chris Hadfield tweeted this photo from the International Space Station, writing, "Tonight's Finale: Southern Ontario, with the hard rock of the Canadian Shield visible from orbit. pic.twitter.com/AWTi9TgAdf"
Priests lay down in front of the altar as Pope Francis celebrates a mass in St. Peter's Basilica at the Vatican, Sunday, April 21, 2013.
Runners observe a 30 second silent in memory of Boston Marathon bombings before the start during the London Marathon, London, Sunday, April 21, 2013.
Astronaut Chris Hadfield tweeted this photo from the International Space Station, writing, "St Lawrence's mouth, where the Great Lakes pour into the sea. pic.twitter.com/4BNeZE59LO"
(Getty Images)
It's a day to celebrate the most famous mother of all: Mother Earth. Monday, April 22, marks the 43rd Earth Day, with more than 1 billion people in 192 countries expected to participate in activities this year.
Though Earth Day is mainstream now, its roots go back to the radical 1960s. So as people break ground for a tree planting or take a few hours to recycle their old laptops, LiveScience looks back at the role Earth Day played in environmental change. From its hippie roots to its global reach, here are five fun facts about Earth Day.
1. Green roots
Earth Day got its start in the wake of the Vietnam War protests of the 1960s. After visiting the site of an oil spill near Santa Barbara, Calif., in 1969, Sen. Gaylord Nelson, a Wisconsin Democrat, envisioned a way to mobilize a grassroots movement to raise the profile of environmental issues, modeled after Vietnam War teach-ins. His idea spread and people held rallies in cities throughout the country on April 22, 1970. [SOS! The 10 Worst Oil Spills]
2. Political impact
Though Earth Day may now be synonymous with small-scale tree planting and volunteer cleanup projects, the first Earth Day actually had its sights set on bigger political projects. Earth Day demonstrations created public support for the creation of the Environmental Protection Agency, authorized by Congress in December 1970. Earth Day also contributed to the passage of the Clean Water, Clean Air and Endangered Species acts.
3. Equinox day
There are actually two Earth Days - the April 22 holiday and the one celebrated on March 20, the first day of spring in the Northern Hemisphere and the autumnal equinox in southern latitudes. To this day, at the exact moment of the equinox, when the sun crosses the plane of the equator and day and night are equal length, the Japanese Peace Bell is rung at the United Nations headquarters in New York City, followed by two minutes of silent prayer or meditation. The Equinox was chosen as a symbol of harmony in nature and an appropriate time to dedicate efforts to peace and care of the Earth.
4. Global Movement
Earth Day may have been conceived in 1970, but it didn't truly go global until 1990. That year, more than 200 million people participated in environmental activities in more than 141 countries. This year, more than 1 billion people are expected to participate in 192 countries.
5. Other holidays
Nelson originally chose April 22 because it didn't seem to coincide with other big holidays in the United States. However, the date was once a big deal in the Communist Soviet Union: it was also the birthday of Vladimir Lenin.
Follow Tia Ghose on Twitter @tiaghose. Follow LiveScience @livescience, Facebook & Google+. Original article on LiveScience.com.
Rivers across the Midwest are topping out at problematic spots thanks to heavy rains and snowmelt in the region. With more rain and snow in the forecast, concerns are growing that the flooding is far from over.
At left, friends and family gather items and check on the submerged home of of Sandra Olson on Sunday, April 21, 2013, in Oquawka, Ill. City officials started receiving calls at 7:15 a.m. that the levee had broken, leaving three homes under water.
The Grand River flows close under the Blue Bridge in downtown Grand Rapids, Mich., on Saturday, April 20, 2013. Hundreds of residents were forced to leave the Plaza Towers and Courtyard Marriott in Grand Rapids after water from the Grand River poured into the basement of the 32-story building Saturday, knocking out electrical service, according to MLive.com. Plaza Towers is shown with no lights since power has been shut off to the building.
The Fulton Street bridge over the flooded Grand River, right, as pictured from the 27th floor of Plaza Towers in Grand Rapids, Mich., Sunday, April 21, 2013. The U.S. 131 bridge is pictured to the left. The Fulton Street bridge has been closed and the Plaza Towers evacuated because of flood waters. Grand Rapids Mayor George Heartwell declared a state of emergency as the flooding Grand River poured into the basements of several hotels and other downtown buildings.
Joe Biggerstaff wades away from his mother's Konkle Drive home on the Grand River north of downtown Grand Rapids, Mich., on Sunday, April 21, 2013. The rising Grand River has driven hundreds of people from their homes in several western Michigan communities and was pushing Sunday toward a record high near Grand Rapids.
This Saturday, April 20, 2013, photo, provided by the Missouri Department of Public Safety shows flooding in LaGrange, Mo. The Mississippi River is topping out at some problematic spots, but there is growing concern that spring floods are far from over. The river was at or near crest at several places Sunday, April 21, 2013, between the Quad Cities and near St. Louis. Some towns in the approximate 100-mile stretch of river from Quincy, Ill., to Grafton, Ill., reached 10-12 feet above flood stage.
This Saturday, April 20, 2013, photo, provided by the Missouri Department of Public Safety shows an overtopped levee north of Clarksville, Mo., and the flood wall protecting the city.
This Saturday, April 20, 2013, photo, shows an aerial view of Clarksville, Mo., and the flood wall protecting the city.
Canoes were the mode of transportation around Des Plaines neighborhoods as Vic Kamka, center, talks to neighbors after flooding along the Des Plaines River on Sunday April 21, 2013. Many of the major roads throughout the town were closed because of flooding.
Four Lakes resident Barbara Joan Boudette talks about the volume and velocity of water from the Dupage River on Sunday, April 21, 2013, which engulfed many Lisle residents continue to battle the effects of this past week's flooding. Flooding is now receding in the town as residents deal with its affects.
Volunteer Phil Rosborough checks the sump pumps around Gurnee Community Church after the building was surrounded by flooding from the Des Plaines River on Sunday, April 21, 2013. "We are keeping the inside dry," said Rosborough. "It is all hands on deck." The downtown area of Gurnee was closed due to flooding.
Des Plaines Public Works trucks pass by stranded vehicles along Rand Road after flooding along the Des Plaines River on Sunday, April 21, 2013.
Konkle Drive resident Kate Krueger removes belongings from the flooded home she rents on the Grand River north of downtown Grand Rapids, Mich., on Sunday, April 21, 2013. She is helped by her friend Wendy Kondracki.
Hector Duran uses his bike to get through floodwater on April 19 in Des Plaines, Ill.
Aerial view of the flooded Riverside Park along the Grand River in Grand Rapids, Mich., Saturday, April 20, 2013. Grand Rapids Mayor George Heartwell declared a state of emergency as the flooding Grand River poured into the basements of several hotels and other downtown buildings.
Michelle VanDuynhoven gives her husband, John, a letter to mail at the bottom of the steps to their home on Stonegate Circle, Saturday, April 30, 2013, in Lincolnshire, Ill. John said there was no water in their house because they rebuilt it higher up in 2010.
Octavio Castillo paddles a boat down a flooded street to reach his cousin's home on April 19 in Des Plaines, Ill.
Rich Sanders checks the level of the water on his boots and decides to walk back to his house on Lincolnshire Way, Saturday, April 20, 2013, in Vernon Hills, Ill. Sanders wanted to checking the water level at the end of the block but turning back on Saturday, April 20, 2013. Rich said his house did not get any water.
This photo shows flooding in LaGrange, Mo. The Mississippi River is topping out at some problematic spots, but there is growing concern that spring floods are far from over. The river was at or near crest at several places Sunday, April 21, between the Quad Cities and near St. Louis. Some towns in the approximate 100-mile stretch of river from Quincy, Ill., to Grafton, Ill., reached 10-12 feet above flood stage.
The Orbital Sciences Corporation Antares rocket is seen as it launches from Pad-0A of the Mid-Atlantic Regional Spaceport (MARS) at the NASA Wallops Flight Facility in Virginia, Sunday, April 21. The test launch marked the first flight of Antares and the first rocket launch from Pad-0A. The Antares rocket delivered the equivalent mass of a spacecraft, a so-called mass simulated payload, into Earth's orbit.
Astronaut Chris Hadfield tweeted this photo of Halifax, Nova Scotia, Canada from the International Space Station on April 22. He wrote, "Tonight's Finale: Halifax, site of NFB Space School launch and final talk with press on Mon. - http://www.asc-csa.gc.ca/eng/media/advisories/2013/0418.asp ... pic.twitter.com/M5uT87gdLi"
A man rests near the collapsed remains of a building hit by an earthquake in southwestern China's Sichuan province, Monday, April 22. Saturday's earthquake in Sichuan province killed at least 186 people, injured more than 11,000 and left nearly two dozen missing, mostly in the rural communities around Ya'an city, along the same seismic fault where a devastating quake to the north killed more than 90,000 people in Sichuan and neighboring areas five years ago in one of China's worst natural disasters.
A Sadhu, or Hindu holy man, performs rituals at Sangam, the confluence of the rivers Ganges, Yamuna and mythical Saraswati in Allahabad, India, Monday, April 22.
Astronaut Chris Hadfield tweeted this photo of the view from the International Space Station on April 22. He wrote, "A glance out the Space Station window is worth taking. pic.twitter.com/4Aiq4NwA7c"
Marc Marquez, of Spain, goes into Turn 20 during the Texas MotoGP motorcycle race at the Circuit of the Americas, Sunday, April 21, in Austin, Texas. Rookie Marquez won a MotoGP race for the first time, capturing the Grand Prix of the Americans on Sunday to become the youngest winner at motorcycle racing's top level.
A honor guard is covered by a flag during a welcoming ceremony for U.S. Joint Chiefs Chairman Gen. Martin Dempsey at the Bayi Building in Beijing, China, Monday, April 22.
Astronaut Clayton C. Anderson tweeted this photo of Earth from the International Space Station on April 22, Earth Day. He wrote, "Earth Day it is! I join the parade & post "cool" space photo from 167 days orbiting our beautifully glorious planet! pic.twitter.com/PU7OAsy4yZ"
Astronaut Chris Hadfield tweeted this photo of James Bay in Canada from the International Space Station on April 22. He wrote, "The face at the mouth of James Bay acts as a symbol today, showing humanity's rock-solid connection to the Earth. pic.twitter.com/iJIVMO9UyG"
