# How big is the retroreflector on the moon?

## How big is the retroreflector on the moon?

105 x 65 cm
The Apollo 15 Lunar Laser Ranging RetroReflector (LRRR) array is one of four such working arrays on the surface of the Moon. As the largest (105 x 65 cm in size) it serves as the primary target for laser ranging to the Moon.

## What did scientists discover about the moon using lunar laser ranging?

Physicists have also used the laser results to check Einstein’s theory of gravity, the general theory of relativity. So far, so good: Einstein’s equations predict the shape of the moon’s orbit as well as laser ranging can measure it.

Is there a retroreflector on the moon?

For decades, scientists have measured the moon’s retreat by firing a laser at light-reflecting panels, known as retroreflectors, that were left on the lunar surface, and then timing the light’s round trip. But the moon’s five retroreflectors are old, and they’re now much less efficient at flinging back light.

What are lunar ranging retroreflectors on the moon used for?

Since 1969, retroreflectors on the Moon have been measuring the distance from Earth with increasing precision. Lunar reflectors left by Apollo astronauts have been used continuously since 1969 to study the earth-moon system and test the validity of the laws of physics.

### How does a retroreflector work?

Retroreflectors reflect incident light back toward the direction of the light source, operating over a wide range of angles of incidence. Typically they are constructed in one of two different forms, 90-deg corner cubes or high index-of-refraction transparent spheres with a reflective backing.

### Which Apollo mission installed a retroreflector on the Moon?

The moonwalking crew of Apollo 11, which landed on the moon 50 years ago this month, put special retroreflectors on the lunar surface, as did the later crews of Apollo 14 and 15, in 1971.

Can a laser touch the Moon?

The typical red laser pointer is about 5 milliwatts, and a good one has a tight enough beam to actually hit the Moonâ€”though it’d be spread out over a large fraction of the surface when it got there. The atmosphere would distort the beam a bit, and absorb some of it, but most of the light would make it.

Can I reflect a laser off the moon?

One of the experiments taken into space on Apollo 11 was called the Lunar Laser Retro-Reflector, and it still works even today (though perhaps not as well as it did), just like it did in a 2010 episode of “The Big Bang Theory.

## What was the purpose of the laser ranging retroreflector?

Description. The laser ranging retroreflector (LRRR), which was left on the lunar surface by the Apollo 11 crew, was a retroreflector array with a folding support structure for aiming and aligning the array toward earth.

## What is unusual about a retroreflector?

A retroreflector doesn’t reflect light in all directions like a dry road, and it doesn’t reflect light away from the source like a flat mirror. Instead, a retroreflector directs the light back towards the source.

Begin typing your search term above and press enter to search. Press ESC to cancel.