Compact X-ray Telescope Could Map Moon's Chemistry

A new compact X-ray telescope could create the first complete chemical map of the Moon's surface. Researchers at Tokyo Metropolitan University used simulations to demonstrate this capability. Such a map would help scientists understand the Moon's formation and evolution.

The simulations indicate that a single telescope orbiting the Moon could map five key elements in about two years. These elements include oxygen, iron, magnesium, aluminum, and silicon. A larger array of 25 detectors could complete the mapping more quickly and with higher resolution.

Mapping the Moon's chemical composition is challenging. Previous missions, like Apollo and Chandrayaan, provided partial maps. However, a full global map has remained elusive. Factors such as limited sunlight-driven X-ray signals and detector degradation in space contribute to these difficulties. The Moon's poles are particularly challenging due to weaker solar X-rays.

The proposed telescope is small and lightweight, weighing less than ten kilograms. It was originally designed for studying Earth's magnetosphere. Its compact size and durability make it suitable for long-term lunar satellite observations. The detector has been tested in harsh radiation environments, exceeding conditions expected in lunar orbit.

The simulations assumed 300 solar flares per year. A single telescope could map the entire lunar surface with a grid size of 70 by 70 kilometers. A five-by-five array of these telescopes could reduce the mission time to one year. With two years of operation, this array could also map sodium and improve the grid size to 30 by 30 kilometers.

This technology could provide a new tool for studying lunar geology. It would help reconstruct the Moon's complex history. The research was supported by the Japan Society for the Promotion of Science (JSPS) KAKENHI Grant Number 21H04972.