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from https://www.forbes.com/sites/startswithabang/2018/12/12/heres-your-proof-that-we-landed-on-the-moon-steph-curry/?sh=66c63b949d9b

Dec 12, 2018,01:45pm EST
Here's Your Proof That We Landed On The Moon, Steph Curry
Starts With A Bang
Ethan SiegelSenior Contributor
Starts With A BangContributor Group
Science
The Universe is out there, waiting for you to discover it.

This article is more than 3 years old.

Apollo 11 brought humans onto the surface of the Moon for the first time
in 1969. Shown here is Buzz... [+] Aldrin setting up the Solar Wind
experiment as part of Apollo 11, with Neil Armstrong snapping the
photograph.

In all of human history, only 24 people have ever flown to the vicinity
of the Moon, traveling hundreds of thousands of miles from Earth to do
so. Twelve of those people, on six independent missions, actually set
foot on the lunar surface. We've left flags, photographs, seismometers, mirrors, and even vehicles behind. We've brought back rocks, dirt, and
literal pieces of the Moon upon our return to Earth.

These monumental moments in history, of landing on the Moon in the late
1960s and early 1970s, are not a part of the memories of the vast
majority of people living today. Unsurprisingly, some of them are
skeptical that it ever happened. Thankfully, in science, we don't need
to be there ourselves to have proof. Here are four different pieces of
evidence we can point to that demonstrate the Moon landings actually
occurred.

This iconic image, taken by Neil Armstrong, shows Buzz Aldrin planting
the US flag on the Moon. Note... [+] the presence of footprints in the foreground. These (and other) astronaut footprints, believe it or not,
are still visible today.

1.) Lunar footprints. Here on Earth, footprints generally don't last
very long. Wherever you leave your tracks, you fully expect that whether
it takes minutes, days, or weeks, eventually the natural phenomena in
the world will cover them up. Winds blowing along the sand dunes, rains
in the forest, or plant and animal activity will eventually eliminate
the evidence of your passing.

All of this happens for a variety of reasons, which include:

the fact that the Earth has an atmosphere,
that we have weather,
that we have liquid water at our surface,
and that we have living species on our world.
So if we walked on the Moon, we would expect those footprints to still
be there.

On Earth, footprints or other markings on the surface are only
temporary, and are easily erased by... [+] the winds, rains, and other
surface activity that comes about on a world with an atmosphere, oceans,
and life. On the Moon, however, those conditions are absent, and any alterations to the surface, even those made by humans some ~50 years
ago, should persist.
On Earth, footprints or other markings on the surface are only
temporary, and are easily erased by... [+] GREG PROHL (L); BYRON
JORJORIAN (R)

Without winds, rains, snows, glaciers, rockslides, or any other means of
moving and rearranging the particles on the surface of the Moon, any
footprints that we left there should remain for an interminable length
of time. The only rearrangement of lunar sand and grains that we know of
occurs when there are impacts on the Moon which kick up dust, which then
can settle across the lunar surface.

Sunlight striking these particles is inefficient; the lunar atmosphere
is only approximately one atom thick; launch and lander activity isn't energetic enough to substantially alter the distribution of material on
the Moon. If we ever landed and traveled on the Moon, the evidence
should still be there.

NASA's Lunar Reconnaissance Orbiter, which has orbited and mapped the
Moon at the highest resolution ever, returning hundreds of Terabytes of
data, has something to say about that.

Apollo 12 was the first precision landing of humans on the Moon, and we explored a much greater... [+] amount of the lunar surface than during
the first landing. The dark grey markings on the surface are astronaut footprints, which have stood the test of time on the Moon, as the
processes that erase them on Earth are absent on the Moon.
Apollo 12 was the first precision landing of humans on the Moon, and we explored a much greater... [+] NASA / LRO / GSFC / ASU
The orbiter's Narrow Angle Camera has photographed three of the landing
sites: Apollo 12, 14, and 17, to unprecedented precision and accuracy.
By going close to the lunar surface and photographing it with modern instruments from that low altitude, they were able to achieve
resolutions as low as 35 centimeters (about 14 inches) per pixel.

The Apollo 12 image shows not only the physical landing site (marked
"Intrepid Descent Stage" on the image), but also the Surveyor 3 probe
that had been on the Moon since 1967, visited by the Apollo 12
astronauts two-and-a-half years later! There's the bright, white "L"
shape near the ALSEP equipment label; the "L" is due to highly
reflective power cables that run from the central station to two of its instruments.

And finally, the dark paths that look like dried-up canals? Those are
astronaut footprints.

The Apollo 14 landing site is still intact, and our images of it in
modern times still carry the... [+] legacy of this nearly-50-years-old
event. The lunar surface changes very slowly over time, and the changes
we made in 1971 are still perceptible, virtually unchanged, today.

The view of Apollo 14 is less spectacular, but perhaps even more famous.
You can still see the descent module and the ALSEP equipment, but
nothing else leaps out at you. Well, except for the footpaths once
again! Whose are they? Edgar Mitchell and the famed Alan Shepard.


Although we never found the golf balls that Alan proclaimed went "miles
and miles" when he hit them with a 6-iron, we can absolutely see the
evidence of the astronauts' presence left behind on the Moon, nearly 50
years later.

A photograph from Lunar Reconnaissance Orbiter of the landing site of
Apollo 17. The tracks of the... [+] Lunar Roving Vehicle (LRV) can be
clearly seen, as can the vehicle itself.

Apollo 17, where Eugene (Gene) Cernan and Harrison (Jack) Schmitt became
the last men to walk on the Moon, paints a notably different picture at
this high resolution. Yes, there's still the descent module on the
surface, the ALSEP equipment and the footpaths. But look closer. There's
also something marked "LRV" as well as a lighter set of two parallel
tracks that run across the surface. Know what they are?

The Lunar Roving Vehicle was included on the last three Apollo missions
and enabled the astronauts... [+] to travel greater distances and
explore more diverse regions of the Moon than they were able to on foot
alone. The tracks of these vehicles are still present today, and can be
seen in data from the Lunar Reconnaissance Orbiter.

The Apollo Lunar Roving Vehicle! Included on Apollo 15, 16, and 17, its
tracks on the surface are distinctly different from human footprints,
and allowed the astronauts on those missions to achieve distances far
greater than those reached on the earlier missions. The tracks from
Apollo 17's LRV don't even come close to fitting in this image; they
extend for a total distance of over 22 miles, reaching a maximum range
of nearly five miles away from the landing site!

Why, what's this? It's an image taken by Bill Anders of Apollo 8: the
first crewed mission to go to... [+] the Moon and orbit it. This photo
was taken as the capsule orbited the Moon and Earth appeared to rise
over the horizon. The spacecraft window can be seen in the foreground.
Why, what's this? It's an image taken by Bill Anders of Apollo 8: the
first crewed mission to go to... [+] NASA / APOLLO 8

2.) Over 8,000 photos documenting our trips. Perhaps we all need a
reminder of what the sacrifices were that went into our journey to the
Moon. We accomplished the unthinkable by banding together to achieve a
common goal, and could do it all once again. NASA has released all the
photos of the twelve Apollo missions that made it to space on a publicly available Flickr photostream, sorted into a series of incredible albums
by mission.

Apollo 10, known as the 'dress rehearsal' for the Moon landing, was
actually equipped with all the... [+] apparatuses that would have
allowed them to land on the lunar surface themselves. They came closer
to the Moon than any previous crewed mission, and paved the way for the
actual moon landing which took place with Apollo 11 in July of 1969.

Some of the greatest, most eye-opening photos, stories and quotes came
back from those trips, including some from Apollo 8's Bill Anders, who
took the famous "Earthrise" photos illustrated above. Anders described
the journey to the Moon as follows:

You could see the flames and the outer skin of the spacecraft glowing;
and burning, baseball-size chunks flying off behind us. It was an eerie feeling, like being a gnat inside a blowtorch flame.

Some of the deployed scientific equipment taken to the Moon during the
Apollo 12 mission, where the... [+] installation and operation of this equipment was well-documented both remotely and in situ by the
astronauts who installed it.

3.) Scientific equipment we've installed on the Moon. Did you know that
we brought up a large amount of scientific equipment and installed it on
the lunar surface during the Apollo missions?

Lunar seismometers were installed by Apollo 11, 12, 14, 15, and 16, with
the most advanced ones transmitting data to Earth until 1977.

Apollo 11 installed the lunar laser ranging retroreflector array, which
is still operational today, allowing us to reflect lasers off of it and
measure the Earth-Moon distance to ~centimeter precision. (We also use
Apollo 14, 15, and the Soviet Lunokhud 2 rover for this.)

The SWC experiment, to measure the solar wind composition from the
Moon's surface.
The SWS experiment to measure the solar wind's spectra from the Moon.
The LSM experiment to measure the lunar magnetic field.
The LDD to measure how lunar dust would settle on and pollute solar panels.

And many others. That we have the data from these experiments, and that
the lunar retroreflectors are still in use today, represent some pretty
strong evidence that we did, in fact, land on the Moon.

This image, from January 31, 1971, shows sunrise from Alan Shepard's 12
o'clock pan taken near the... [+] Lunar Module at the start of EVA-1 (moonwalk). Without the Sun glare, we can see some detail on the
Cone-Crater ridge. The flag, S-Band antenna, ladder, and the LRRR (Laser Ranging Retroreflector) are all located in the west footpad. The MET
(Modular Equipment Transporter) has not been deployed and is still
folded up on the MESA (Modular Equipment Stowage Assembly).

4.) We brought back samples, and learned a ton about lunar geology from
them. The final two astronauts to ever walk on the Moon, Gene Cernan and Harrison Schmitt, ran into quite a surprise when they did. Schmitt, the
lone civilian-astronaut (and only scientist) to travel to the Moon, was
often described as the most business-like of all the astronauts. Which
is why it must have been such a shock to hear him exclaim the following:

Oh, hey! Wait a minute… THERE IS ORANGE SOIL! It’s all over! I stirred
it up with my feet!

The dull, grey lunar soil you’re used to seeing — that we’re all used to seeing — in one particular spot was only a very thin veneer, covering a
rich, orange landscape beneath.

The orange soil, at the lower right of the image, really stands out when compared to the colorations... [+] visible on the rest of the Moon.
Apollo 17, perhaps because they had a geoscientist as one of their
moonwalkers, was able to spot this geological oddity that taught us so
much about the Moon's origin and composition.

Like any good scientist, or any good explorer, for that matter, Cernan
and Schmitt took pictures, collected data, and brought samples back to
Earth for further analysis. What could cause orange soil on the Moon,
perhaps the most featureless of all the large, airless rocks in our
Solar System?

What the analysis back on Earth revealed was fantastic: this was
volcanic glass. What occurred was that molten lava from the interior of
the Moon erupted, some 3 to 4 billion years ago, up above the airless
surface and into the vacuum of space. As the lava became exposed to the
vacuum, it separated out into tiny fragments and froze, forming tiny
beads of volcanic glass in orange and black colors. (The tin in some of
the fragments is what gives the orange color.)

Olivine inclusions found in lunar samples have a spectacularly high
water concentration of 1,200... [+] ppm. This is remarkable, because
it's the same exact concentration as the water found in terrestrial (Earth-based) olivine inclusions, pointing to a common origin for the
Earth and the Moon.

In 2011, reanalysis of those samples found evidence that water was
included in the volcanic eruption: with concentrations of water in the
glass beads that were formed 50 times as great as the expected dryness
of the Moon. Olivine inclusions showed water present in concentrations
up to 1,200 parts-per-million.

Most remarkably, the lunar samples we've found have indicated that Earth
and the Moon have a common origin, consistent with a giant impact that
occurred only a few tens of millions of years into the birth of our
Solar System. Without direct samples, obtained by the Apollo missions
and brought back to Earth, we never would have been able to draw such a startling, but spectacular, conclusion.

A NASA picture taken on May 5, 1972 shows a close-up view or 'mug shot'
of Apollo 16 lunar sample... [+] no. 68815, a dislodged fragment from a
parent boulder. A fillet-soil sample was taken close to the boulder,
allowing for study of the type and rate of erosion acting on lunar rocks.

There are many different lines of evidence that point to humanity's
presence on the Moon. We landed there and can see the evidence,
directly, when we look with the appropriate resolution. We have
extraordinary amounts of evidence, ranging from eyewitness testimony to
the data record tracking the missions to photographs documenting the
trips, all supporting the fact that we landed and walked on the lunar
surface. We have a slew of scientific instruments that were installed,
took data, and a few of which can still be seen and used today. And
finally, we've brought back lunar samples and learned about the Moon's
history, composition, and likely origin from it.

There are many ways to prove it, but the conclusion is inescapable: we
really did land on the Moon, and we can validate it yet again by
performing the right scientific test — through imaging or laser ranging
— any time we want.

Follow me on Twitter. Check out my website or some of my other work here.
Ethan Siegel
Ethan Siegel
I am a Ph.D. astrophysicist, author, and science communicator, who
professes physics and astronomy at various colleges. I have won
numerous... Read More

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