The five reflectors on the moon
Moon away
A group of scientists has been studying for about four decades to measure the moon's decline in orbit or the moon's continuous distance from Earth by firing a focused beam of laser beams on reflective panels known as "reference reflectors".
It is the five reflectors placed by the first astronauts in the Apollo flights, on the surface of the moon at precisely defined locations, with the aim of measuring the duration and time of the light journey from the earth to the moon and vice versa.
However, during the laser tests, they notice that the aforementioned five moon reflectors have become old over time, and have also become less effective in sending light back in the opposite direction to the planet.
Lunar reference reflectors
They are reflective devices with a special design and were installed in five different areas on the lunar surface by the astronauts from the successive Apollo flights.
And with reflectors on the moon, scientists were able to accurately record measurements of the changing distance between the Earth and the Moon.
The monitoring and study has been repeated from several different sites and time periods over the past four decades..but
? What is the reason for the low effectiveness of lunar reflectors
Lunar dust
In an attempt to reach the causes and the truth about whether layers of lunar dust, fine and diffuse, are responsible for this shortcoming in performing its mission to reflect the laser, the scientists involved in the study thought of implementing another plan, which was as follows:
They fired a beam of light from a laser at a much smaller reflector than the lunar reflectors, which are disrupted by lunar dust, but this small reflector is of the most modern type. The time, and despite the difficulty of the experience, they succeeded in implementing this alternative plan....
Study of the reference reflectors of the moon
The findings of this study were published in this month's issue of the journal Earth, Planets and Space
(Earth, Planets and Space), which deals with specialized astronomy studies. These are the five reference reflectors that were installed on the lunar surface by the Apollo 1 astronauts and unmanned Soviet spacecraft.
One of the most important scientific instruments on the lunar surface, which human astronaut teams left on the lunar surface during their mission, are these reflective panels
It simply performs a similar function to the tape measure that we use in our lives, and through it, astronomers and physicists can accurately measure the distance between the moon and planet Earth, and this is done by determining the time it takes for the laser beam emitted from the earth to reach the surface of the moon, reflect on its surface, and then return Once again to the surface of the earth, and this trip takes place in about (2.5 seconds), of course, half the time to go and half of it to return from the moon.
?How does a ray of light bounce off the moon
This light reflection occurs thanks to the multi-faceted combination of cubic glass corners.
These photonic devices respond to incoming light in the opposite direction in the direction it came from, ensuring that return reflectors send out photons of light in a narrow, precise detour. Over time, these repeated calculations will allow researchers to paint a clear picture of the Moon's orbit, its exact orientation in space, and even its internal composition.
New reflective panels
But the Lunar Reference Reflectors, the size of your travel bag, which reached the Moon between 1969 and 1973, suffered from the signs and symptoms of obsolescence.
Tom Murphy, a physicist from the University of California, San Diego, who was not involved in the study, revealed that "the effectiveness of reference reflectors is only a tenth of what scientists expect from them, and the light reflections back to Earth through them are very weak." It is probably due to the accumulation of lunar dust on it, which is usually produced by meteorites that hit the surface of the moon.
This dust covered the uniforms of the astronauts during their visits to the moon, even when they returned to the spacecraft. It spread inside, and space scientists expect that it will cause great problems if humans think about the stability of the moon.
Lunar orbiter (Europater)
It's been nearly 50 years since the spacecraft was outfitted with a single reference reflector the size of a large paperback cover. The ship, dubbed the Lunar Reconsence Europeter, orbits the Moon every two hours and has so far provided Earth with millions of high-resolution images of its surface. The moon and its terrain in detail...
The spacecraft provides an "ideal target," said Irwan Mazariko, a planetary scientist at NASA's Goddard Space Flight Center. ». It should be noted that Mazariko, along with his colleagues, are testing the hypothesis that lunar dust is the reason for disrupting the power of the moon's reflectors.
The reflector is a moving target
But this reflector is at the same time a moving target, as «Europater» revolves over the surface of the moon at a speed of 5793.6 km per hour.
That's why Murphy, who leads the Apache Point Observatory for Lunar Laser Operations, better known as the "Apollo" thinks.
(a project using reflectors on the lunar surface), that "hitting a moving target is very difficult." For this reason, we intend to use a smaller system while allowing it to move around.
Targeting the new Europter reflector
In 2017. Mazzarico and his partners began firing an infrared laser light from a station near Grasse, France, about a half hour's drive from Cannes, toward a reference reflector on the ship.
On September 4, 2018, at 3 a.m., scientists recorded their first success, detecting 25 photons that had completed their round-trip. The researchers also had three additional hits through the fall of 2019. After calculating the smaller size of the reference reflector on orbit, Masariko and his colleagues found that it returned photons more efficiently than the Apollo reflectors. So far, there's little evidence to blame lunar dust for the declining performance of reflectors on the lunar surface, according to Mazariko, who revealed that they are gathering more information. But Murphy and other scientists believe the recent findings of the study have helped clarify the picture further. He added, "For me, the results of the new study tip the scales in favor of the theory that lunar dust is the reason for the decrease in the moon's reference reflectors.
Source: websites