In 1970, millions of Americans concerned about the environment observed the first 'Earth Day.' Forty-four years later, the tradition and message of conserving our beautiful planet is still going strong. On Tuesday, April 22, NASA released a photo of the Americas captured by NOAA's GOES-East satellite to commemorate the occasion.
Above, take a look through some of the splendid photos of Mother Earth that have been shot from outer space through the years. From the original Blue Marble photo shot back in 1972 to the new high-definition Blue Marble images to a screen shot of the very first video image of Earth taken by a weather satellite in 1960, the photos are breathtaking on any day, but take on a special meaning on Earth Day.