Prior to his Apollo 15 lunar mission, astronaut David Scott met Belgian painter and printmaker Paul Van Hoeydonck at a dinner party. It was there agreed that Van Hoeydonck would create a small statuette for Scott to place on the Moon, though their recollections of the details differ. Scott’s purpose was to commemorate those astronauts and cosmonauts who had lost their lives in the furtherance of space exploration, and he designed and separately made a plaque listing fourteen American and Soviet names. Van Hoeydonck was given a set of design specifications: the sculpture was to be lightweight but sturdy, capable of withstanding the temperature extremes of the Moon; it could not be identifiably male or female, nor of any identifiable ethnic group. According to Scott, it was agreed Van Hoeydonck’s name would not be made public, to avoid the commercial exploitation of the US government’s space program. Scott got permission from top NASA management prior to the mission to take the statue aboard his spacecraft, but did not disclose it publicly until a post-mission press conference.
Launched as GRAIL A and GRAIL B in September 2011, the probes were renamed Ebb and Flow by schoolchildren in Montana. The probes operated in almost circular orbit near the lunar poles at an altitude of approximately 34 miles, until their mission came to an end in December 2012. The distance between the twin probes altered a bit as they soared over areas of lesser and greater gravity that were caused by visible topological features on the Moon's surface, such as impact craters and mountains--as well as by masses that were secreted beneath the lunar surface.
The tiny moon--which for now has been designated S/2015 (136472) 1, and playfully nicknamed MK 2, for short--is more than 1,300 times dimmer than Makemake itself. MK 2 was first spotted when it was about 13,000 miles from its dwarf planet parent, and its diameter is estimated to be about 100 miles across. Makemake is 870 miles wide, and the dwarf planet, which was discovered over a decade ago, is named for the creation deity of the Rapa Nui people of Easter Island.
"For the smaller craters, it's like if you're filling a bucket, eventually your bucket gets full, but if you keep pouring cups of water into the bucket, you can't tell how many cups of water beyond full you've gone. Looking at the larger craters at the subsurface might give us insight, because that 'bucket' isn't full yet," Dr. Soderblom added.