NASA has sent Lunar Reconnaissance Orbit (LRO) in orbit around the moon in 2009. Post which, scientists have started to firing lasers for getting a reflection.
After almost 10 years, scientists have finally got some photons reflected at the Earth. The reason behind so late in getting photons is the small size of reflector array comparable to a paperback book. This is going to be very helpful in not only performing measurements of and around the Moon but also in understanding the conditions on the lunar surface that might degrade the machines put over 50 years ago.
Why Laser Reflectors are used?
The laser reflectors are used because it helps in measuring the accurate distance between two points, depending upon the speed-of-light. This measures far distance from the Moon, with millimeter precision. This measurement can also tell whether the moon has a fluid core or solid material analyzing the revolve of the moon. This precise measurement also tells that Moon is moving far away from the Earth at a speed of 3.8 centimeters per year.
Introduction of LRO Reflector
One problem that has occurred with lunar reflectors is that the return of light gets dimed by 10 percent which tells about the presence of dust on the Moon. This is why the LRO reflector has been introduced. This will help in determining the reason behind the surface reflector’s declining efficiency and amount of micrometeorite bombardment.
Signals Received by LRO Reflector
However, LRO’s reflector is also challenging as it is very small (15 by 18 by 5 centimeters) and fast-moving. After the unsuccessful of green light, infrared-light was used for LRO reflector as it can penetrate gas and cloud. The Laser Ranging Station in Grasse, France had recorded the first infrared laser light bouncing back from LRO. Again on 23 and 24 August 2019, the result was repeated.