This view of Earth, featuring North, Central and South America was taken by the NASA probe called Messenger, while conducting a fly-by of our planet in order to pick up a gravity-assist boost on its way toward Mercury. (NASA/Johns Hopkins University Applied Physics Laboratory/Carnegie Institution of Washington)

Two days ago it was the 40th Earth Day and we've already spoken about it here.
To celebrate it, The Big Picture, in my opinion one one of the best photoblog of the web, have prepared a gallery of 40 images,
"each a glimpse into some aspect of the world around us, how it affects and sustains us, and how we affect it."
Just as I expected a half of them are strictly related to water and it's anything but a surprise given the key-role that H20 has in our planet...
Enjoy the pics, and check the original The Big Picture's gallery for all the others images.

This undated handout photo provided by the journal Science shows Iron oxides staining the snout of the Taylor Glacier, in the McMurdo Dry Valleys, Antarctica, forming a feature commonly referred to as Blood Falls. The iron originates from ancient subglacial brine that episodically discharges to the surface. Outflow collected at Blood Falls provides access to a unique subglacial ecosystem that harbors a microbial consortium which actively cycles iron, sulfur and carbon for growth. (AP Photo/ Science, Benjamin Urmston)

Local miner Cesar Abac uses a wooden bowl and mercury to pan for gold near at the village of Las Cristinas, southern Bolivar State, Venezuela on January 30, 2009. Four centuries after the lure of Venezuelan gold brought ruin to English explorer Sir Walter Raleigh, the riches at one giant mine some say is cursed still haunt treasure hunters from across the globe. But the Las Cristinas saga, involving a ghost town, environmental devastation and fist-sized nuggets, underlines the risks of business in Venezuela, where the draw of natural wealth has been dulled by rule changes and economic turmoil. (REUTERS/Henry Romero)

This photo from 1997, released by Woods Hole Oceanographic Institution shows the robotic arm of a three-person submersible aquatic vehicle reaching toward a hydrothermal vent in the east Pacific Ocean far off the coast of Chile. New technology and worldwide demand for metals have combined to make deep ocean mining of the mineral-laden liquid spewed from these vents a possibility. (AP Photo/Woods Hole Oceanographic Institution, Pat Hickey)

A humpback whale raises its tail as it prepares for a deep dive in the Santa Barbara Channel off the coast of Oxnard, Calif. on Sunday afternoon, April 19, 2009. The offshore oil platform "Gail" is seen in the background. (AP Photo/The Santa Barbara News-Press, Mike Eliason)

Analyzing a variety of samples from the atmosphere above the Amazon, Ilan Koren and colleagues at the Weizmann Institute in Israel, show in the journal Science that smoke and other so-called "aerosol" particles can encourage or discourage cloud formation, depending on the conditions, and a their new scientific model shows how these two processes produce a joint effect on climate. (Science/AAAS)

Snow-covered pine trees sit in flood water March 31, 2009 near Moorhead, Minnesota. A snowstorm had slowed recovery efforts as residents of Moorhead and neighboring Fargo, North Dakota returned to their homes as the Red River slowly receded. (Scott Olson/Getty Images)

A North Dakota Air National Guard helicopter carries six 1,000-pound sandbags to the edge of the Clausen Springs dam Wednesday, April 15, 2009, as an attempt was being made to control the erosion of the emergency spillway. (AP Photo/ The Forum, Dave Wallis )

An enormous iceberg, right, breaks off the Knox Coast in the Australian Antarctic Territory on Jan. 11, 2008. (AP Photo/Torsten Blackwood, Pool

Minnows are deposited through a tube from a tanker truck into Lake Delton as area officials take the first steps in restocking the lake, Monday, April 20, 2009, in Lake Delton, Wisconsin. The minnows will serve as food for larger game fish to be stocked in June. A section of the manmade lake's shore washed away during thunderstorms last June, and the entire lake drained through the opening. (AP Photo/Morry Gash)

A Kenyan fisherman holds a fish that had escaped from his fishing net, Saturday, Feb. 28, 2009 in the waters of Diani on the Kenyan south coast. Plastic fishing nets, some bought for poor fishermen with American aid money, are tangling up whales and turtles on Diani, one of Africa's most popular beaches. (AP Photo/Karel Prinsloo)

A bird flies past dumped plastic bottles and other garbage on the bank of the river Sava in Belgrade, Serbia on April 22, 2009. (ANDREJ ISAKOVIC/AFP/Getty Images)

Residents walk in debris after a dam burst in Jakarta, Indonesia, Sunday, March 29, 2009. Attention shifted to caring for homeless and hungry survivors after the dam burst outside the Indonesian capital, sending a wall of water crashing into homes and killing at least 91 people, and leaving more than 100 others missing.(AP Photo/Tatan Syuflana)

Lebanese workers use water pressure to clean-up the oil spill which polluted Rabbit Island, offshore the Nothern Lebanese city of Tripoli, on March 31, 2009. The oil spill was caused by the explosion of fuel reservoirs stationed in the southern coastal town of Jiyyeh during the Israeli offensive on Lebanon in July 2006. (Georges Haddad/AFP/Getty Images)

Tropical Cyclone Billy, off the coast of Western Australia on December 25, 2008. (NASA image by Jeff Schmaltz, MODIS Rapid Response Team, Goddard Space Flight Center)

Dead carp are seen in the "Las Tres Pascualas" lagoon in Concepcion city, some 322 miles (519 km) south of Santiago, Chile on March 30, 2009. Environmentalists say a clandestine dumping of sewage in the lagoon led to the waters being polluted and caused the high rate of fish mortality, local authorities said. Picture taken March 30, 2009. (REUTERS/Jose Luis Saavedra)

Russian Emergency Ministry staff watch a blast ripping through the ice covering the Kan river in the town of Kansk some 220 km (136.7 miles) from the Siberian city of Krasnoyarsk April 4, 2009. Explosive experts used dynamite to break the ice cover to ease pressure that could cause floods as melting snow increases the river's water volume. (REUTERS/Ilya Naymushin)

Rescuers work to keep alive one of the 17 long-finned pilot whales that were being battered by rough seas after they were beached in Hamelin Bay, Western Australia on Monday, March 23, 2009. About 80 whales and dolphins were stranded on the remote southwest Australian beach where authorities tried to truck the few survivors to a protected bay before attempting to launch them back to sea. (AP Photo/Steve Mitchell)

Elang, an Indonesian student, swims in foamy, polluted waters after school, at the Pluit Dam in Jakarta, Indonesia on April 20, 2009. (REUTERS/Beawiharta)