Image of the Day: A Lunar Rainbow!


The LROC's Wide Angle uses filter to capture image, capturing three different wavelengths: a 689nm filter for red, a 643nm filter for green, and a 604nm filter for blue. To get one image, the spacecraft camera shoots three consecutive image, which are then combined by the computer to create one single images.

When the Sun is directly overhead the Lunar surface, with the LRO in between, a phenomenon called "opposition surge" happens—a sudden increase in the surface brightness, with no shadows on the surface. As the light reaches the LROC's camera, it interferes with itself. And as this happens, the filters change, capturing the shining at sightly different moments. When the software combines the resulting images, you can observe the light shifting in the form of a rainbow.

According to Brett Denevi at the LROC blog, the images "provide a huge new dataset for studying how light interacts with a particulate surface at different wavelengths. Perhaps an esoteric-sounding field of study, but this data can help us understand the reflectance images and spectra we have of the Moon and other bodies throughout the Solar System."

Casey Kazan via gizmodo and LROC


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