The first Earthrise to be witnessed by a human
Forty years ago, the biggest TV audience in history tuned in to watch humankind's first close encounter with another world, as the crew of Apollo 8 reached lunar orbit. Here, the Apollo historian and film-maker Dr Christopher Riley gives his perspective on the mission and how that Christmas Eve of 1968 changed the world.
Back in 1948, the British astrophysicist Sir Fred Hoyle predicted that when spaceflight enabled us to see the whole Earth from space, the view would change us forever.
Hoyle would have to wait another 20 years before humans would get to see this view with their own eyes, when the crew of Apollo 8 became the first astronauts to leave Earth orbit.
By then, a handful of satellites had snapped a number of breathtaking portraits of the Earth from afar and even a stunning shot of the Earth rising above the Moon's surface from lunar orbit.
But on Christmas Eve 1968, none of the astronauts on board Apollo 8 were ready for the opportunity to witness their own Earthrise.
In all the months of training and preparation which had preceded the mission, no-one had thought to schedule an attempt for the crew to glimpse and record the most moving of sights, as their jewel of a home planet, suspended in the blackness of space, rose from behind the barren lunar horizon.
http://news.bbc.co.uk/2/hi/science/nature/7797439.stm