A new map of the Moon has revealed an abundance of titanium orethat is up to 10 times richer than on Earth, a finding that could one day lead to a lunar mining colony, astronomers said on Friday.
The discovery was made thanks to a camera aboard the US Lunar Reconnaissance Orbiter, which swept the surface of the Moon, scrutinising it in seven different light wavelengths.
Mark Robinson of Arizona State University, who presented the research at a conference in Nantes, western France with Brett Denevi of Johns Hopkins University in Baltimore, sifted through the data for telltale jumps in the ratio of ultra-violet to visible light.
They established this signature thanks to rock samples brought back to Earth by Apollo 17 astronauts in 1972 and images of the area around the mission's landing site by the Hubble space telescope.
"Looking up at the Moon, its surface appears painted with shades of grey, at least to the human eye," explained Robinson.
"But with the right instruments, the Moon can appear colourful.
"The maria [lunar plains] appear reddish in some places and blue in others.
"Although subtle, these colour variations tell us important things about the chemistry and evolution of the lunar surface. They indicate the titanium and iron abundance, as well as the maturity of a lunar soil."
Titanium is as strong as steel but nearly half as light, which makes it a highly desired -- and also very expensive -- metal.
On Earth, titanium is found, at the very most, in around one percent of similar types of ore. But the new map found abundances in the lunar maria that range from about one percent to 10 percent, the conference organisers said in a press release. In the lunar highlands, abundance was around one percent.
The meeting gathers, for the first time, members of the European Planetary Science Congress and the American Astronomical Society's Division for Planetary Sciences.
The find offers a double potential bounty, they said.
"Lunar titanium is mostly found in the mineral ilmenite, a compound containing iron, titanium and oxygen," they said.
"Future miners living and working on the Moon could break down ilmenite to liberate these elements.
"In addition, Apollo data shows that titanium-rich minerals are more efficient at retaining particles from the solar wind, such as helium and hydrogen. These gases would also provide a vital resource for future human inhabitants of lunar colonies."