to nearly everyone the moon appears to
be a sterile gray unchanging world
but while the moon has remained largely
unchanged during human history our own
understanding of it has evolved
dramatically
thanks to new observations we now have
not only unprecedented views of its
surface but a whole new tour of the moon
that shows how both it and other rocky
planets in our solar system have been
shaped over billions of years
we'll start with one of the largest
impacts oriental basin a feature that's
as wide as the distance from new york
city to cincinnati using new elevation
measurements we can clearly see the
effects of what is likely the last giant
impact event in lunar history with its
outer mountain rings rising many
kilometers above the lowest points
inside the crater
the interiors of some craters in the
moon's polar regions like shackleton
haven't seen sunlight in over 2 billion
years
however new measurements have created
our best yet maps of these types of
craters allowing us to see deep into the
shadows of this surprisingly young
looking impact crater in the south
that's more than twice as deep as the
grand canyon
some impacts are invisible for other
reasons although the ancient south pole
aitken basin is difficult to see from
orbit because it is so large
new lro topography maps reveal the
largest impact basin in the earth moon
system measuring several kilometers in
depth and around 2500 kilometers in
diameter
only the helis basin on mars rivals it
in size
one of the youngest large-scale impacts
on the moon is the tycho crater this
fresh crater may have formed only 108
million years ago when dinosaurs roamed
the earth we now also have an extreme
close-up view of the crater's central
peak revealing a mountain with sharp
edges building-sized rocks and a central
boulder about the size of a baseball
stadium
the aristarchus plateau is another
recent lunar formation that has long
interested scientists and astronomers
the crater itself formed in the same era
as the tycho crater and what appear to
be snaking river valleys were actually
carved by ancient lava flows
next we arrive at mayor serenitis on the
near side of the moon
in december of 1972 the crew of apollo
17 landed in the taurus littrow valley
marking the last time humans have
visited the surface of the moon
with images from lro's narrow angle
camera we can clearly see the evidence
of that visit
in this image you can easily see the
base of the lunar lander along with the
lunar rover parked far from the blast
off zone
you can also clearly see the astronaut
trails and the wheel tracks left on the
lunar surface
we now head to the far side of the moon
which cannot be seen from earth
our first stop is the compton belkovitch
region which shows evidence for young
volcanic activity in the far side
highlands
this feature is unique not only because
it is isolated from other volcanoes in
the area but also because it is located
nowhere near the maria where volcanoes
are usually found
also on the far side we find the jackson
crater which like the tycho crater on
the near side has an extensive and
complex ray system
in fact this crater is often considered
to be like a twin to tycho
finally the silkovsky crater stands out
as an excellent example of a far side
crater filled with a sea of ancient lava
known as amare it is particularly
interesting to scientists and other
observers because of its isolation from
other similar craters as well as its
beautiful central
peak as we continue to study the moon
our understanding of it improves giving
us new insights not only into how it has
evolved over time but also how other
rocky planets in our solar system have
come to look the way they do
with new missions new instruments and
new technologies we will continue to
improve our knowledge of the moon
and better understand the history of our
solar system
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