Earth Day

Earthrise is a photograph of the Earth and parts of the Moon's surface taken by astronaut William Anders in 1968, during the Apollo 8 mission as the first manned orbit of the moon. It has been considered to be the most influential environmental photograph ever taken.

The whole opportunity was almost overlooked as is illustrated by the recorded conversation between Apollo crew members, Frank Borman and William Anders, during the taking of the Earthrise photograph;

Anders: Oh my God! Look at that picture over there! There's the Earth coming up. Wow, is that pretty.
Borman: Hey, don't take that, it's not scheduled. (joking)
Anders: (laughs) You got a color film, Jim?
            Hand me that roll of color quick, would you...
Lovell: Oh man, that's great!

The colour photograph with the earth just touching the horizon was taken from lunar orbit on December 24, 1968, with a highly modified Hasselblad 500 EL with an electric drive. The camera had a simple sighting ring rather than the standard reflex viewfinder and was loaded with  custom Ektachrome film developed by Kodak.

The Blue Marble, so called because of its striking appearance and perceived size to the observing Astronauts  is a famous photograph of the Earth, taken on December 7, 1972,  at 5.39am Eastern Standard Time by the crew of the Apollo 17 spacecraft, at a distance of about 45,000 kilometers (28,000 miles).

It is one of the most iconic, and among the most widely distributed images in human history.

The image with the official NASA designation AS17-148-22727 reproduces the view of the Earth as seen by the Apollo crew travelling toward the Moon. The translunar coast photograph extends from the Mediterranean Sea to Antarctica.

This was the first time the Apollo trajectory made it possible to photograph the south polar ice cap with the Southern Hemisphere heavily covered in clouds. Almost the entire coastline of Africa is clearly visible and the Arabian Peninsula can be seen at the northeastern edge of Africa. The large island off the coast of Africa is Madagascar. The Asian mainland is on the horizon toward the northeast. An Indian Ocean cyclone can be seen in the top right of the image. This storm had brought flooding and high winds to the Indian state of Tamil Nadu on December 5, two days before the photograph was taken.

The photographer used a 70-millimeter Hasselblad camera with an 80-millimeter Zeiss lens. Such is the iconic status of the photograph that NASA credited it to the entire Apollo 17 crew—Eugene Cernan, Ronald Evans and Jack Schmitt—all of whom took photographs during the mission with the on-board Hasselblad, although evidence examined after the mission suggests that Jack Schmitt was the photographer.

Apollo 17 was the last manned lunar mission. No human since has been far enough from Earth to photograph a whole-Earth image such as The Blue Marble, but whole-Earth images have been taken by many unmanned spacecraft missions.

This was the case with the Pale Blue Dot ,a photograph of planet Earth taken on February 14, 1990, by the Voyager 1 space probe from a record distance of about 6 billion kilometers (3.7 billion miles).
In September 1977, NASA launched Voyager 1, a 722-kilogram (1,592 lb) robotic spacecraft on a mission to study the outer Solar System and eventually interstellar space.

The spacecraft, travelling at 40,000 miles per hour (64,000 km/h), is the farthest man-made object from Earth and the first one to leave the Solar System. Its mission has been extended and continues to this day, with the aim of investigating the boundaries of the Solar system, including the Kuiper belt, the heliosphere and interstellar space. Operating for 38 years, 10 months and 6 days as of today (July 13, 2016), it receives routine commands and transmits data back to the Deep Space Network.

After encountering the Jovian system in 1979 and the Saturnian system in 1980, the primary mission was declared complete in November of the same year. Voyager 1 was the first space probe to provide detailed images of the two largest planets and their major moons.

Voyager 1, which had completed its primary mission and was leaving the Solar System, was commanded by NASA to turn its camera around and take one last photograph of Earth across a great expanse of space, at the request of astronomer and author Carl Sagan.

In the photograph, Earth's apparent size is less than a pixel; the planet appears as a tiny dot against the vastness of space, among bands of sunlight scattered by the camera's optics.

Sagan's words are an epic statement, inspirational and thought provoking;

"We succeeded in taking that picture, and, if you look at it, you see a dot. That's here. That's home. That's us. On it, everyone you ever heard of, every human being who ever lived, lived out their lives. The aggregate of all our joys and sufferings, thousands of confident religions, ideologies and economic doctrines, every hunter and forager, every hero and coward, every creator and destroyer of civilizations, every king and peasant, every young couple in love, every hopeful child, every mother and father, every inventor and explorer, every teacher of morals, every corrupt politician, every superstar, every supreme leader, every saint and sinner in the history of our species, lived there – on a mote of dust, suspended in a sunbeam"

(sources; wikipedia, BBC Radio Five Drive, Carl Sagan, NASA)