Earth From Afar – Tales Of The Blue Marble

A composite picture of the Earth's western hemisphere taken on January 4, 2012 by the Suomi NPP satellite. Click to enlarge. Credit: NASA/NOAA

Have you ever taken a portrait of yourself and a friend holding a camera at the end of your arm? Who hasn’t these days? It has to be the numero uno category of photos seen on Facebook. NASA got into the act too, only the “arm” is a satellite and the “friend” is planet Earth.

Earth's eastern hemisphere compiled from photos taken by Suomi NPP. The hazy streaks are sunglint from reflection of the oceans. Click to enlarge. Credit: NASA/NOAA

The agency released two new pictures taken by the most recently-launched Earth observing satellite Suomi NPP that show our planet in all its green, brown and blue glory. Suomi NPP snaps images of Earth in 1,865-mile-wide swaths from a 512-mile-high orbit that takes it over the north and south poles. Each swatch is imaged through red, green and blue filters and later combined into a natural color photo. In the eastern hemisphere image, pictures from six orbits of the satellite on January 23 were compiled via special data processing to let us see Earth from nearly 8,000 miles away instead of the satellite’s strict 512 mile altitude.

Another composite map of Earth made in the early 2000s using pictures by the Terra satellite. Click and then select different resolutions to see larger maps for each month. Credit: NASA

Ten years ago thousands of photos snapped by the Terra satellite were stitched together with 3-D software to create monthly maps of the entire planet. To watch the changing seasonal colors and snowpack, click the photo above and you’ll be taken to a page with maps for each month. Click HERE to find out how it all was accomplished.

One of the few single images (not a composite) of planet Earth shot on color film by the Apollo 17 crew. It was taken shortly after the spacecraft left its parking orbit around Earth en route to the moon. Click to enlarge. Credit: NASA

Since satellites orbit relatively near Earth, to get a really good view of our world, you’ve got to step way back or have a very long arm. The very first picture showing the planet in its entirely was taken on December 7, 1972 by the Apollo 17 astronauts at a distance of 28,000 miles. Nicknamed the “Blue Marble”, it’s one of the most widely-circulated photos on, well … Earth.  Antarctica, Madagascar (right), the outline of Africa and Saudi Arabia all show beautifully.

Looking at Earth never gets old. It’s also refreshing. Missing in every photograph are all the borders and boundaries that can make life so confounding.

6 Responses

  1. Travis Kitch

    Hi Bob,

    Finally, a clear night here in western MN and a chance to see that gorgeous moon. Wow! Nice article on images of Earth from afar. Seeing pictures like the ones you posted always remind me of Sagan’s Pale Blue Dot speech.

    Seeing the moon tonight reminded me of an archaeological artifact that I often show my students ( Perhaps you have seen it before. This little piece of eagle bone is perhaps 30-odd-thousand years old and the markings on it have been interpreted (by some, not certainly by all) as an ancient lunar calendar. Your thoughts?


    1. astrobob

      Hi Travis,
      Very interesting artifact. I’ve heard of it but never studied it closely. I wish I could see the 29 day moon cycle in it, but it’s not clear to my eye. Looks like the piece could be interpreted in other ways. I would guess that at the very least, it was used to count something. Do you know where I can find Marshack’s original paper?

  2. Travis Kitch

    Hi Bob,

    Marshak’s original paper (published in 1964 I believe) is fairly obscure and very short (only two pages). I think the American Association for the Advancement of Science (AAAS) might have it on their webpage but you might need to be a member to get access. Anthony Aveni, in his 1993 book Ancient Astronomers (Smithsonian Books), nicely summarized Marshak’s arguments, however. The eagle bone, part of a wing, was found in central France. Marshak initially used a 1960’s-era microscope to study the engravings. Originally the artifact was thought to have been used as a tool sharpener, but Marshak argued that each marking denoted a single day and that the “days” were connected in a single sinuous line (whoever engraved the bone would have rotated the object in his or her hand to accomplish this). He then went to count and clump the “days” into groups of 15s and 30s, coinciding with new and full phases of the moon.

    As far as I’m concerned we have no valid way of substantiating (or refuting) this claim. This artifact was made over 30,000 years and we have no idea what the rationale and thought process of the maker of the object truly was.

    Interesting food for thought, however.


    1. astrobob

      I agree, it’s great food for thought. Certainly a possibility but I suspect we’ll never know. Thanks again for bringing up the topic.

  3. fabian

    Admiro mucho su trabajo, y pues la verdad no tengo estudios que me permitan opinar aecerca de todo lo que he podido observar en su blog pero felicitaciones por todo lo que a podido ivestigar, averiguar y analizar; grcias por lo que nos ha podido mostrar y epero que pueda seguir publiando cosas asy de interesantes

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