NASA EPIC Sunlit Full Earth Images Every Two Hours From 1 Million Miles

Summary: NASA's EPIC sunlit full Earth images every two hours from 1 million miles have been taken daily since July 6, 2015, via NOAA's DSCOVR satellite.

NASA's first EPIC sunlit full Earth image, taken on July 6, 2015, presents North and Central America as viewed from a distance of 1,000,000 miles: NASA/Goddard Space Flight Center/EPIC, Public Domain, via NASA

NASA’s EPIC sunlit full Earth images, taken every two hours at a distance of almost one million miles via NOAA’s Deep Space Climate Observatory (DSCOVR) satellite, have been documenting the photogenic Earth’s daily variations since Earth Polychromatic Imaging Camera’s first captures on July 6, 2015.

Jay Herman, EPIC’s lead investigator, explains the wonders of EPIC’s revelations at a media briefing on Monday, Dec. 14, during the annual fall meeting of the American Geophysical Union in San Francisco.

He describes: “With EPIC, you see cloud structure from sunrise on the left to sunset on the right. It’s the only view we have like this where everything is at the exact same instant in time, even though the local times are different.”

The first EPIC sunlit full Earth image, returned to NASA on July 6, 2015, is a photogenic portrait of North and Central America, with hints of South America’s west coast. The scattering of sunlight by air molecules is responsible for the image’s characteristic bluish tint. NASA’s EPIC team aims to remove the bluish atmospheric effect from subsequent EPIC images.

DSCOVR’s location at the Earth-sun Lagrange-1 (L-1) point provides EPIC with a unique angular perspective for EPIC’s 10-channel measurements of aerosols, cloud reflectivity, cloud heights and vegetation properties. The balance between the sun’s and Earth’s gravitational forces at the L-1 point allows for a stable orbit by DSCOVR on Earth’s sunward side. The orbital position is ideal for DSCOVR’s primary mission of monitoring incoming solar wind and serving as an early warning system for solar wind-driven geomagnetic storms on Earth.

EPIC’s 10 narrowband filters span the spectrum from ultraviolet to near infrared. Images posted to NASA’s EPIC dedicated website, launched Oct. 19, 2015, are drawn from blue, green and red channels. Resolutions range between 6.2 and 9.4 miles (9.98 to 15.12 kilometers) per pixel.

EPIC’s ultraviolet channels track the day-long, westward travels of Saharan dust across the Atlantic.

“We can see the progression in real time, as it flows across the Atlantic,” notes Jay Herman.

A comparison of EPIC images at two different wavelengths allows for determining the height and location of daytime clouds. Cloud measurements are integral to Earth energy balance calculations and to weather tracking. For example, a high cloud spiral forms around a hurricane’s clearly discernible eye.

EPIC’s field of view (FOV) of 0.62 degrees sufficiently images the Earth’s entire, 0.5 degree-sized, sunlit face. DSCOVR’s tilted orbit around L-1 accounts for apparent angular size variations from 0.45 to 0.53 degrees during the satellite’s six-month orbital period.

Alexander Marshak, DSCOVR deputy project scientist, explains the wonders of discovery gifted by EPIC sunlit full earth images: “Because of the unique location and field of view, every day brings something new and unexpected.”

image of lunar far side, illuminated by the sun, as the moon crosses between Earth and the DSCOVR spacecraft's Earth Polychromatic Imaging Camera (EPIC) camera and telescope, one million miles away: NASA/NOAA via NASA

Acknowledgment

My special thanks to talented artists and photographers/concerned organizations who make their fine images available on the internet.

Image credits:

EPIC sunlit full earth image: NASA/Goddard Space Flight Center/EPIC, Public Domain, via NASA @ http://www.nasa.gov/image-feature/nasa-captures-epic-earth-image

image of lunar far side, illuminated by the sun, as the moon crosses between Earth and the DSCOVR spacecraft's Earth Polychromatic Imaging Camera (EPIC) camera and telescope, one million miles away: NASA/NOAA via NASA @ https://www.nasa.gov/feature/goddard/from-a-million-miles-away-nasa-camera-shows-moon-crossing-face-of-earth

For further information:

Cole, Steve. "The EPIC view of high clouds, Saharan dust." NASA Global Climate Change. Dec. 14, 2015.
Available @ http://climate.nasa.gov/news/2374/

Cole, Steve, and Rani Gran. "NASA Studies High Clouds, Saharan Dust, from EPIC View." NASA Press Release. Release 15-220. Dec. 14, 2015.
Available @ http://www.nasa.gov/press-release/nasa-studies-high-clouds-saharan-dust-from-epic-view

Fox, Chloe. "NASA Captures EPIC Views of Earth." HuffPost Science. Dec. 14, 2015.
Available @ http://www.huffingtonpost.com/entry/epic-views-of-earth-nasa_566f5930e4b0e292150ef0da?utm_hp_ref=science&ir=Science&section=science

Gutro, Rob. "From a Million Miles Away, NASA Camera Shows Moon Crossing Face of Earth." NASA > NASA Goddard. Aug. 5, 2015.
Available @ https://www.nasa.gov/feature/goddard/from-a-million-miles-away-nasa-camera-shows-moon-crossing-face-of-earth

NASA‏ @NASA. "Taking pics of Earth every 2 hrs, EPIC camera will give new insights on our changing planet." Twitter. Dec. 14, 2015.
Available @ https://twitter.com/NASA/status/676456813533900800

NASA Goddard. "NASA / EPIC Observations Pouring In." YouTube. Dec. 14, 2015.
Available @ https://www.youtube.com/watch?v=XGJ-RZglvKo

Northon, Karen, ed. "NASA Captures 'EPIC' Earth Image." NASA. July 20, 2015. Last updated July 30, 2015.
Available @ http://www.nasa.gov/image-feature/nasa-captures-epic-earth-image

"What is EPIC?" NASA Goddard Space Flight Center EPIC.
Available @ http://epic.gsfc.nasa.gov/epic.html