Monday, October 26, 2015

Self-absorbed Earth takes tons of selfies

OK, so maybe the Earth isn't actually self-absorbed or taking selfies, but the humans located on its surface want a blue marble-like picture of the Earth on a daily basis. NASA (the humans) isn't taking just one Earth-selfie a day... they're snapping at least 12 images of the completely sun-lit side of the Earth throughout the course of a day as the Earth rotates.

Selfie! Sequence of natural-color images from Oct. 17, 2015 from the EPIC camera aboard DSCOVR.

The iPhone camera, is located one million miles away (over 4 times the distance from the Earth to the Moon) aboard the Deep Space Climate Observatory (DSCOVR). The overall purpose of the spacecraft is to detect and provide advanced warning of Earth-directed space weather caused by the Sun. In addition, DSCOVR observes Earth in order to measure reflected sunlight and re-emitted radiation from the surface of the Earth. 

The Earth Polychromatic Imaging Camera (EPIC) is a spectroradiometer and images in 10 narrow spectral bands ranging from the near-infrared (0.764 and 0.779 micrometers) through the visible (0.443, 0.552, 0.680, and 0.688 micrometers) and into the ultraviolet (0.317, 0.325, 0.340, and 0.388 micrometers) portion of the electromagnetic spectrum. From the vantage point of EPIC at LaGrange-1 point, NASA has a continuous and simultaneous view of the sun-lit side of the Earth. They are able to obtain images with high temporal (1-day return) and relatively high spatial resolution (24 km after compression) covering half of the Earth's surface in one shot! Previously, this was only achieved by stitching many photos together from satellites orbiting much closer to Earth. 

These images of Earth are extremely useful for climate studies. Scientists can monitor the concentration levels of water vapor, ozone and aerosols in the atmosphere, the amount of UV radiation reaching the Earth's surface, cloud cover and cloud heights, albedo, and the overall energy balance of the Earth system. One exciting benefit for scientists is that the data obtained by EPIC will overlap the data coming from low-Earth and geostationary satellites (e.g. Landsat, MODIS) and can be used for comparison and missing data due to near-Earth satellite return times.

Image of North and South America from October 25, 2015 taken by EPIC camera.

View recent and archived natural-color images of Earth from EPIC here!

Original source:

Additional sources (not already linked to in post): 

No comments:

Post a Comment