Moon Zoo and Moon Mappers crowdsource lunar craters

Explore the Moon in the Moon Zoo and Moon Mappers crowdsourcing projects. These projects let you map features in detailed pictures from the Lunar Reconnaissance Orbiter. The catalogs of lunar features you create will help scientists understand our closest neighbor in space and the history of the Solar System.

Geologists uncover Earth’s history as they dig through strata laid down by sediment and lava. They measure the chemical composition, fossil records, and atomic isotopes to reconstruct Earth’s four billion year history. That’s a luxury planetary scientists don’t have. Despite decades of space exploration, planetary scientists have barely scratched the surface. Instead they must rely on indirect measurements captured in cameras and other instruments. That’s where craters come in. A region with a few clearly-defined craters must be younger than a region with many craters layered on top of each other. The dark areas on the Moon, the maria, are young surfaces created when lava covered lowland basins. You see fewer craters in the maria than in the older lunar highlands. 

The Moon plays a special role in crater studies. Unlike other objects in the Solar System, scientists have direct access to lunar material. Nasa’s Astromaterials Acquisition and Curation Office holds over 380 kilograms of lunar samples gathered by the Apollo astronauts. Planetary scientists can make the same direct measurements geologists use to study Earth. Comparing these measurements to data from orbiting space probes lets them draw relationships between cratering and the Moon’s age. The lunar relationships underly crater studies of other moons, planets, and asteroids throughout the Solar System. Counting the craters in space probe images ought to be the job of computer algorithms. Software can process more images faster than people. But software struggles with crater-counting. Shadows change the appearance of craters while layers of dust and debris mask old craters.

The Zooniverse and CosmoQuest crowdsourcing services know amateur space explorers can do the job better. Both the Moon Zoo and Moon Mappers projects ask you get to map the location and size of the craters and other interesting features in high resolution images from the Lunar Reconnaissance Orbiter. Both projects want to create better lunar crater catalogs to improve our understanding of the Moon’s history and improve crater studies of other objects. Although similar, the two projects have different goals. 

Moon Mappers' scientists plan to improve automated algorithms’ ability to map smaller craters. The project asks you to map craters as small as ten meters across.The Moon has billions of craters that size - and billions more that are smaller. Amateurs produce more accurate results than software, but the tens of thousands of amateurs in the project will never map every crater on the Moon. In cases where scientists can trade accuracy for volume, software works fine. But it could be better. The accurate maps amateurs create lets Moon Mapper scientists test and improve the software they write.

Meanwhile, Moon Zoo's goals focus on other aspects of lunar geography. The Moon Zoo catalog will let them develop theories about the production of craters smaller than one kilometer. They also want to study the depth of regolith, the crushed rock and dust created by four billion years of asteroid bombardment. Regolith depth is another way to estimate a region’s age. Asteroid impacts in younger regions with thin regolith layers produce craters that look different from the craters in older regions with thick regolith layers.

The Moon Zoo blog and Moon Mappers blog share the latest updates from the project team, but the best part of being an amateur crater counter is joining the community. Hundreds of discussions take place in the Moon Zoo Forum and the Moon Mappers Forum. Fellow amateurs share tips on crater counting and explain the features that appear in the Lunar Reconnaissance Orbiter images. Professional scientists also turn to the amateurs in these forums for help on other lunar exploration projects. Researchers at Aberystwyth University in Wales investigate transient lunar phenomena, bright patches that briefly appear on the lunar surface. These may be created by gases released from lunar lava tubes or landslides. The Aberystwyth scientists created a Moon Zoo Forum thread where amateur crater counters post images containing these lunar features. That gives the scientists targets for their telescope observations. 

The amateur crater-counters at Moon Zoo have submitted over 3.7 million classified images around the Apollo 17 and Apollo 12 landing sites. The amateur Moon Mappers have contributed over one million crater counts of their own around the Apollo 15 landing site. Scientists at the University of Colorado recently looked at how well the amateurs at Moon Mappers perform compared to expert crater analysts. You can read (for a fee) the full peer-review article or the shorter paper (free) presented at the 2014 Lunar and Planetary Science Conference. They found no difference between the accuracy of amateur crater-counters and expert planetary scientists. 

All told, the two projects have mapped less than one percent of the Moon’s surface. Billions more lunar craters remain unmapped, waiting for your contribution to space exploration.