In 2009 the Lunar Reconnaissance Orbiter (LRO) was launched by NASA. Its mission was to map the moon’s surface and collect measurements on possible scientific targets as well as landing sites. After over two years in an almost circular polar orbit, LRO changed into an elliptical polar orbit. As a result of this orbital change, the LRO was able to capture images from the moon’s northern hemisphere. The craft used a Wide Angle Camera (WAC) and two Narrow Angle Cameras (NACs) to obtain the images of the lunar terrain. The Lunar Reconnaissance Orbiter Camera (LROC) achieved the results of complete image coverage of the moon from 60°N to the lunar north pole. The only areas not covered are those which are in permanent shadow. The LROC took 10,581 images which have now been released as an interactive mosaic of the northern pole of the moon.
The images were taken over a period of four years and possibly comprise one of the world’s largest mosaics in existence. It is available to the public on the web and includes more square footage than Alaska and Texas combined. There are over 680 gigapixels of image data. The compressed mosaic size is 950 Gigabytes. For the sake of perspective, if the complete image file were combined and printed out at a resolution of 300 dots per square inch, the entire printed paper would be almost as long as a professional U.S. football field and actually wider. If the entire mosaic were saved as a single image, the file size would need to be saved on the order of 3.3 terabytes of storage.
However, the mosaic was processed and divided into millions of smaller images which were compressed and released for end-users to view the moon images as well as interactively navigate through them using their home based web browser. Home users will be able to see the end results of this massive four year effort. The interactive map was created not only by the images captured by the cameras but by using data from LRO’s Lunar Orbiter Laser Altimeter and information from the Gravity Recovery and Interior Laboratory (GRAIL) mission which was launched September 2011. The GRAIL mission was tasked with producing a gravity field map of our lunar body in order to determine the interior structure.
John Keller, NASA’s LRO project scientist at Goddard Space Flight Center indicates that this project is simply the latest example of data products that LRO has supplied for a good portion of the last five years. The actual mosaic, according to Mark Robinson, who is the lead investigator for the LROC team located in Tempe at the Arizona State University, took a large team and four years to create. They are looking at the images and the mosaic as something that will be beneficial for future moon explorations. Additionally, the images may provide insight as to the most favorable future landing spots.
The Lunar Reconnaissance Orbiter was both designed and manufactured by Malin Space Science Systems. It is managed at the NASA Headquarters in Washington by Goddard for the Science Mission Directorate. The now released interactive moon mosaic may be viewed on the LROC website.
By Dee Mueller