The X-ray instrument on board the Chandrayaan-1 spacecraft orbiting the moon was switched on and successfully detected its first X-ray signature from the moon. The C1XS X-ray camera, (pronounced like “kicks”) detected the X-ray signal from a region near the Apollo landing sites on December 12th 2008 at 02:36 UT. The solar flare that caused the X-ray fluorescence was exceedingly weak, approximately 20 times smaller than the minimum C1XS was designed to detect, which is good news for the sensitivity of the instrument. “C1XS has exceeded expectations as to its sensitivity and has proven by its performance that it is the most sensitive X-ray spectrometer of its kind in history,” said Ms. Shyama Narendranath, Instrument Operations Scientist at the Indian Space Research Organisation (ISRO).
The instrument will help map out the composition of the Moon in much greater detail than has ever been done, and could help settle a long-running debate about how the Moon formed.
The leading theory of how the Moon was created is that a Mars-sized object slammed into the Earth early in its history, creating our orbiting moon. A better accounting of the Moon’s makeup is needed to solidify the theory.
A few other spacecraft, like Chandra have taken X-ray images of the moon, but X-ray imaging from Earth is impossible because our atmosphere cuts out X-rays from space.
The C1XS will work by looking at the X-rays from our sun that have been absorbed by atoms in the lunar soil, then re-emitted in such a way as to reveal the chemistry of the surface. The spectrometer is sensitive to magnesium, aluminium and silicon x-rays.
Barry Kellett, instrument scientist from the UK’s Science and Technologies Facilities Council said, “Despite the small quantity of data, our initial analysis and modeling shows that C1XS has identified the chemistry of this area of the Moon.”