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Practice English Speaking&Listening with: What Did We Leave on the Moon & What Will Happen to it in the Future?

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With the surprise landing of a Chinese Rover Yutu 2 or the Jade rabbit 2 and

the Chang'e lander on the far side of a moon on the 3rd of January

2019, I thought it'd be interesting to see what sort of things we've actually

put up on the moon and to speculate on what might happen to them in the future.

Now it will come as no surprise that the Apollo missions have left behind the

most amount of items but long before they were even thought of the Soviets

pulled off something that not for the first time the U.S. thought they

couldn't actually do. In 1959 the Soviet Luna 2 probe was the first man-made

object to intentionally impact on to the lunar surface, the closest to the US had

got to the moon by then was with a pioneer for but that was 60,000

kilometers away which was a bit of a shock because the U.S. believed that

while the Soviets had bigger rockets they were lacking the precision in their

navigation and guidance systems. Although these early probes were

designed to crash into the moon, in a piece of pure propaganda Luna 2 left

behind a calling card to remind everyone else that they were here first.

Luna 2 was loaded not only with experiments but two small spheres one 7.5 cm

and the other 12 cm across and made from

pentagonal pennants each stamped with the insignia of the Soviet Union and the

date 1959 on the larger of the two. These spheres had an explosive core and were

designed to explode and scatter the pennants on impact. Although these were

the very first man-made items to make it to the moon their fate is unknown as Luna 2

impacted a speed of around 3.3 km/s about 12,000 kilometers an hour and

was probably vaporized on impact. A third sphere was in the Luna twos rocket

body which crashed about 30 minutes later that was filled with liquid and

aluminum strips with the year 1959 and Union of Soviet Socialist Republics

engraved upon them. As the space race intensified the lunar research also

increased the U.S. sent the Ranger probes to take close-up images of a moon

they did this like the soviet lunar probes by crashing into the moon whilst

transmitting live TV signals back to earth. At one point it was called the

"shoot and hope" program because the first six out of nine range probes either

failed on the launch pad, missed the moon completely or failed before reaching the

moon's surface. This was followed up by the surveyor program to find out more

about the actual surface and potential landing sites for Apollo as it was

feared by some but any Lander would just sink and disappear into the lunar dust

five out of the seven surveyors successfully landed and proved that

theory was groundless. Also around his time the lunar orbiter program was the

first NASA craft orbit and survey the moon including mapping its gravitational

field again for the Apollo missions. After their missions were complete the

orbiters were deorbited and crashed into the moon so they wouldn't pose any

threat to the Apollo missions. With the lunar orbiters one, two and three ending up on

the far side of the moon. The Soviets had a similar hit and miss success rate with the

first four attempts of a soft landing failed. Finally on the 3rd Feb 1966

lunar 9 became the first lunar lander to achieve and survive a soft landing.

Something which is often overlooked is it the rockets that carried the

spacecraft also ended up on the moon. The third stage of the Saturn V that

carried the Apollo missions 11, 13, 14, 15, 16 and 17 also crashed into the moon and

some of their positions are well known. Apollo 12 third stage was planned to go

into a solar orbit but due to venting of his fuel tanks it didn't have enough

propellant and ended up in a stable orbit between the earth and the moon.

Even though Apollo 13 never landed its spent third stage was detected hitting

the surface and the impact crater has been captured by the Lunar

Reconnaissance Orbiter camera some 135 kilometers away from the Apollo 12 site.

Apollo 12 and all the following missions left behind the ALSEP or Apollo Lunar

Surface Experiments Package. This included a range of experiments like the

seismometer which picked up the Apollo 13 third-stage impact

as well as other devices through the analysis of micro meteorites, the moon's

gravity, magnetic field, solar radiation, atmosphere and internal structure. Apollo

11 left behind the lunar laser ranging experiment which is the only lunar

experiment still to be working today and uses an earth-based laser to measure the

distance from the earth to the moon with an accuracy of about three centimeters.

The Apollo missions landed with a complete lander but they couldn't return

in the same way, only the ascent stage of the lander took off to return the crew

and they had a very strict weight limits too much weight and they might not make

it back to the command module literally every kilogram made a difference and

that was a reason for leaving behind the seemingly random list of objects as we

will see later. Once the crews had transferred from the ascent module to the

command module, the ascent modules were released to crash back onto the lunar

surface except to Apollo 13 which was used as a lifeboat to get the crew back

to earth and burned up in the Earth's atmosphere and Apollo 10. Apollo 10 was a

complete dress rehearsal for Apollo 11 except for the landing. Gene Cernan and

Thomas Stafford took the lunar lander to within 15 kilometers of the surface

before returning. In fact the ascent stage was deliberately short fueled to

stop the crew from attempting a landing on the moon because if they did they

wouldn't have enough fuel to make it back to the command module. The Apollo 10

descent stage was left in orbit but fell back to the moon and it's position is

unknown. After the crew had transferred the ascent stage nicknamed "Snoopy" fired

its engine until it ran out of fuel this sent it out into an orbit around the Sun

and it's still there, somewhere, in an orbit slightly shorter than that of

the Earth, the only manned spacecraft left in space without a crew. If you look

at the inventory of items left behind for each mission you'll see a lot of

really rather mundane items. Things like filters, urine and defecation

bags, food bags, chair arm rests, towels, batteries, earplugs, brushes, boots, tongs,

tools, scales in fact over eight hundred items. NASA has created a twenty two page

document listing everything on the moon which you can download and peruse for

yourself but there are also some things that you think they would like to bring

back like the Hasselblad cameras which were used to take on average fifteen

hundred photos each but no they left behind 12 of the 14 taken on the Apollo

missions. The astronauts were instructed to bring back just the film canisters

and leave the cameras to make room for rock samples, This allowed an extra 25

kilograms of rocks to be brought back over six missions in place of the

cameras. Of course some things were just far too big to bring back like the three

lunar Rovers along with their TV cameras they were left behind to film the ascent

from a moon by remote control on earth. There was also a gold-plated telescope,

the only one to make observations from a surface of a celestial body other than

the earth. Other things left behind were symbolic in nature and were not always

officially sanctioned. We all know the U.S. flags but Apollo 11 also left

behind a gold olive branch as a representation of peace. An Apollo 1

patch to honor the crew of Grissom, White and Chaffey who died in a fire during

testing and medals given to the families of the deceased cosmonauts Gagarin and

Komarov. There is also the moon memorial disk which contained the goodwill

statements by President Eisenhower, Kennedy, Johnson and Nixon and messages

from the leaders of 73 countries from around the world. The disc was made using

the same techniques as early integrated circuits and is the size of a U.S.

50-cent coin with the writing visible using a microscope. On Apollo 15 a nine

centimeter statue called "Fallen Astronaut" along with a plaque

commemorating the 14 US and Soviet astronauts which died during training

was unofficially placed on the moon by David Scott

and on Apollo 16 Charlie Duke left a photo of himself his wife and two

children on the surface. On the back he wrote "This is the family of astronaut

Charlie Duke from Planet Earth who landed on the moon on April 20 1972"

During and after the Apollo missions the Soviets continued with their

remote-controlled lunokhod Rovers 1 and 2 in 1970 and 1973. Lunokhod 2

operated for four months traveling 42 kilometers and sending back 86 panoramic

images and 80,000 TV pictures. Since then there have only been satellites from the

US, Japan, India and China most of which are which have ended up on the surface

until December 2013 when the Chinese became only the third country to soft

land on the moon with the Chang'e 3 and the Yutu or Jade rabbit Rover.

Although the rover succumbed to a mechanical abnormality probably caused

by the lunar dust after two months, the lander which is powered by radioisotope

thermoelectric generator and solar cells was still in contact with the ground

control some four and a half years after it landed and in theory its power supply

could last for 30 years. So what will happen to the things left on the moon.

Some say that with no erosion, no wind, rain or volcanic activity they will be

there long after the human race has come to an end in the millions or even

billions of years into the future but they are forgetting a few things. Firstly

the lunar dust, it covers the entire moon and was created and still is being

created by meteor impact. Although there is no wind to move it around it

becomes electrostatically charged from the sun's ultraviolet and x-ray radiation.

This causes it to levitate and create a very thin atmosphere of dust constantly

rising and falling around the terminator' line as it sweeps across the

surface from lunar day to lunar night. Recent observations and experiments show

that the dust builds up at a rate of around about one millimeter per

thousand years. Now that sounds like a tiny amount but in a million years all

the items on the moon would be under a meter of dust and that's assuming we

didn't do anything to make it worse. If we start mining on the moon then the

amount of dust raised will be much much more and with only one-sixth gravity

and no air resistance it could also travel a very long way. Then there is the Sun

with no protective atmosphere like the earth anything on the surface is exposed

to the full force of the sun's ultraviolet, x-ray and ionizing charged

particles just look at its effect here on earth on paint pigments and photos

that have been left out in the Sun. That lack of atmosphere also means there is

almost no temperature regulation so in direct sunlight the surface can reach a

127 C and at night it can drop to minus 173 C

The thermal stress of that 300 degree temperature range would also take

its toll on anything left there. The photo that Charlie Duke left 47 years

ago is probably completely bleached by now as are the u.s. flags and pigments

and painted surfaces will have degraded and is also the sandblasting effect of

micro meteorites hitting objects directly or nearby and lunar dust which

is highly abrasive. So while they may well in some ways last a lot longer than

they would do compared to being left outside on earth, they will meet the same

fate and eventually crumble to dust. One of the reasons for Apollo leaving so

much stuff on the moon was the limited weight they could carry back in the

ascent module with every kilogram making a difference they had to choose what to

bring back and what to leave these were just some of the myriad of problems that

had to be solved often with very short notice on the missions themselves not

only for Apollo but for every lunar mission that's ever been attempted. If

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