Planetary scientists at Brown University have developed a new remote sensing technique for studying a mineral on the moon called olivine. The researchers say olivine could help them understand the early evolution of the moon and other planetary bodies. This mineral is important because it is known to be an important part of the rocky planet’s interior.
Christopher Kramer, lead author of the new paper describing the work, said olivine is the main component of the Earth’s mantle and has been detected on the surface of the moon and Mars. Olivine has been detected in volcanic sediments or impact craters that take material out of the ground. Currently, remote sensing is enough to find olivine from orbit, but scientists want to do more than just discover the mineral.
The researchers hope to learn more about the chemical composition of olivine. They point out that all olivine has silicon and oxygen, but some are rich in iron and some are rich in magnesium. The composition of olivine reveals the environment in which they form, especially the temperature. The higher the temperature during formation, the greater the magnesium content, and the lower the temperature, the greater the iron content.
By understanding the composition of olivine on the moon, Mars, and other planetary bodies, scientists can learn more about the evolution of planetary bodies as they form. One way to study rocks on other planets is spectroscopy. Different elements or compounds absorb or reflect different wavelengths of light to varying degrees. By looking at the spectrum of rock reflections, scientists can understand their composition.
Kramer observed a small range of light wavelengths between the infrared spectrum and the mid-infrared spectrum. He found that among these wavelengths, there was a band between 4 and 8 microns that predicted magnesium or iron levels in olivine samples up to less than 10% of the actual content. Instruments now available can analyze “what elements” are available, but the new process allows researchers to analyze quantitative data, an important advance in astronomical exploration.