The mission captured by the twin probes' cameras documents the final journey of the Grail spacecraft, which had aimed to map the moon's gravity field. NBC's Brian Williams reports.
NASA's Grail mission bit the moondust last month — but images captured by the twin probes' cameras bring the yearlong lunar mission back to life in a two-minute video documenting one of Grail's final go-arounds.
Grail's main aim was to map the moon's gravity field, as reflected in the acronym behind the mission title (Gravity Recovery and Interior Laboratory). There was an educational angle as well, pioneered by Sally Ride, America's first woman in space. As the founder of Sally Ride Science, the late astronaut was in charge of Grail's MoonKam educational project, which let students pick out targets for the black-and-white cameras mounted on the two probes (nicknamed Ebb and Flow).
Three days before the Grail probes made their crash landing on Dec. 17, mission controllers activated the cameras on one of the probes to take some parting shots of the lunar surface from a height of about 6 miles (10 kilometers). The picture-taking session was part of the equipment checkout conducted in preparation for the planned mission-ending impact into a mountain near the moon's north pole.
NASA's Jet Propulsion Laboratory assembled almost 2,500 of those images into the video released Thursday, which shows a stretch of the northern hemisphere on the moon's far side in the vicinity of Jackson Crater.
The first part of the clip, comprising 931 images, shows the terrain as seen by the Ebb spacecraft's forward-facing camera. The scene immediately shifts to the view from Ebb's backward-facing camera head for another 1,498 images. The video runs six times faster than the real-time voyage took.
Doug Ellison, a visualization producer at JPL, worked on the Grail video and said on Twitter that it was "one of my favorite projects to be involved with."
Three days prior to its planned impact on a lunar mountain, mission controllers activated the camera aboard one of NASA's GRAIL twins to take some final photos from lunar orbit.
He acknowledged that the picture quality might not come up to the standards of, say, NASA's $720 million Lunar Reconnaissance Orbiter mission. But after all, the cost of the cameras accounted for just a small portion of Grail's $500 million mission cost.
"The cameras were an education and outreach addition, purely for the use of the MoonKam project," Ellison pointed out on YouTube. "Middle school students scheduled observations with these cameras — more than 100,000 images in all. Yes, they are small, crumby pictures. They are also infinitely more inspiring to the middle school students that commanded them than not having images at all."
The MoonKam images prove that even low-cost, low-tech cameras can heighten interest in space science. "Their shortfalls in terms of fidelity and quality speak to the engineering of the mission itself," Ellison said. "I like that."
More about the Grail mission:
- Grail impact site named after Sally Ride
- Gravity map reveals our battered moon
- Kids get their very own 'Earthrise'
Alan Boyle is NBCNews.com's science editor. Connect with the Cosmic Log community by "liking" the log's Facebook page, following @b0yle on Twitter and adding the Cosmic Log page to your Google+ presence. To keep up with Cosmic Log as well as NBCNews.com's other stories about science and space, sign up for the Tech & Science newsletter, delivered to your email in-box every weekday. You can also check out "The Case for Pluto," my book about the controversial dwarf planet and the search for new worlds.