When you look at the moon, just remember
that somewhere on lunar face the
remains of Apollo 11, 12, 14, 15, 16 and 17
along with eight unmanned Russian lunar
missions and five pre Apollo unmanned
American surveyor missions are all still
there silently looking back, unless of
course you're a NASA non-believer.
So why can't we see these from Earth,
why can't we train our best telescopes
on to the moon's surface and see them
exactly where we left them the best part
of 50 years ago.
Well there's a bit of a problem and that
is that the moon is 384,000 kilometers
or 238,000 miles away and the Landers
and all the things that behind are just a
few meters across. To give you an idea of
just how difficult this problem is it's
like looking for an object size of a
coin from a thousand miles away or the
equivalent from New York to Florida, so
you need a pretty serious telescope. One
telescope which springs to mind is the
Hubble Space Telescope, after all if it
can see galaxies billions of light-years
away then it should be able to see the
Apollo landings easily.... shouldn't it.
Well as with many things to do with
space is not that simple.
Yes, the hubble space telescope was indeed
designed to look at very faint objects
at astronomical distances but those
objects are clusters of galaxies
trillions of miles across, it was just
not designed to take high-resolution
images of small objects are fairly close
ranges in astronomical terms like to the
moon.
The problem is down through a resolution
of the images at the telescope produce
and that is ultimately limited by the
law of physics. The resolution determines
the smallest picture element or pixel in
the image the higher resolution the more
the fine detail image can be seen.
In a telescope the bigger the mirror the
more of a magnification so the closer
the object will appear but very large
magnifications be images also affected
by the wavelength of light itself
shorter the wavelength of light like
ultraviolet light a fine of a detail
that can be captured and the resolution
increases but invisible light as we go
from blue to green to red, the wavelength
increases and a resolution is actually
decreased. The Hubble has a mirror which is
2.4 meters in diameter which was the
largest that will fit into space shuttle
by when it was placed in orbit.
This gives it a single pixel resolution
in ultraviolet light of about 43 meters
across on the moon surface, anything
smaller than 43 meters will just be
hidden in a single dot which cannot
resolve any further. In fact we need
really two pixels or more to make out
anything at all. In visible light it's
even worse and the size of the area
covered by a single pixel increases 90
meters. The only way we're going to see
any object few meters across on the
lunar surface is either to increase the
size of a mirror or get closer to the
object we're looking at. Back on earth
the current largest optical telescope in
the world is the GTC on the Canary
Islands with a mirror diameter of 10.4
meters. This increases the resolution
so that the smallest area covered by one
pixel will be 20 meters across invisible
light still too big to see the Apollo lander
which is just over 4 meters across.
In fact to see the Apollo landers from
Earth you need a telescope with a mirror
size 10 times that of GTC or about 100
meters across and that does not yet
exist. Even with a 100 meter telescope
would only give you a two meter
resolution coverage so the lander would be
two pixels in visible light and four
pixels in ultraviolet light, still not
enough to discern any real detail. This
is the reason why we are unable to see any
of the vehicles on the moon from the
earth and although in theory it is
possible to use a group of telescope in
an array to get a higher resolution,
no one has yet done it because telescope
time is in very high demand and very
limited and looking for objects that we
know already exists is just not a high
enough priority just to disprove that
none believers. What we need to do is put
a camera in orbit around the moon just
like the spy satellites or the ones which
gives the satellite mapping services
like Google Earth for example. In 2009
that's exactly what happened when the
Lunar Reconnaissance Orbiter or LRO was
launched to photograph and survey the moon
from a distance between 12 and 100
miles above its surface. Even
with a much smaller camera lens, at its
closest passes,
it has a resolution of just 0.5 meters
or 18 inches per pixel.
So now all of the Apollo sites with the
lunar landers, the rover's as well as the
russian site can now be seen for the
first time since they landed. This also
shows the trails left in the lunar dust
by the astronauts both on foot and in
the lunar Rovers, the science experiments
that were left there over 44 years ago
are still visible and even the shadows
of the American flags can be seen as they
vary in size due to the changing position of
the Sun during lunar. Day we can't
see the flags themselves because they
are hanging vertically and the camera is
looking for top down position
and the flags for just a fraction of an
inch thick. So now we have the
photographic evidence of the Apollo
landers, unless of course you don't
believe anything official that comes out
of NASA and that they were placed
there by robotic Landers or aliens years
later or the moon is a hologram and
the earth is flat.
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