Friday, October 23, 2015
A New Blue Marble Every Day
The Blue Marble photograph of Earth must be one of the most iconic images from the second half of the Twentieth Century. This stunning picture of the Earth was taken on December 7th 1972, from a distance of about 28,000 miles from Earth, by the crew of the Apollo 17 spacecraft.
Since 1972 images of the whole sunlit side of the Earth have tended to be composite mosaic pictures made up of a number of different satellite images of the Earth stitched together. This is because the majority of satellites which orbit the Earth do so at too close a distance to be able to capture a photo of the entire Earth.
NASA's EPIC (Earth Polychromatic Imaging Camera) aboard the Deep Space Climate Observatory (DSCOVR) has begun sending home new Blue Marble images of the Earth. DSCOVR's orbit is about one million miles away from Earth. It also maintains a fixed position in terms of the Earth, which means it can take whole photos of the sunlit side of the Earth every few hours.
You can now view and download EPIC's daily 'Blue Marble' images from the NASA website. DSCOVR::EPIC allows you to view a day's worth of whole Earth photographs, revealing the whole globe over the course of a day. If you press the forward button on the website the photos will animate through the whole day's images of the Earth. An inset mapped globe also rotates to show which continents are currently in view in each picture of the Earth.