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♪♪♪

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In December 2018, after traveling for two years,
one hundred and one days,

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and over one-point-two billion miles…

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NASA’s OSIRIS-REx spacecraft arrived at its target:
near-Earth asteroid Bennu.

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OSIRIS-REx is the first mission to explore this
primitive remnant

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from the origins of the solar system, designed to study
the asteroid and return a sample to Earth.

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Bennu is a dark, diminutive world, roughly the
height of a skyscraper,

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and now, the smallest body to be orbited
by a spacecraft.

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Prior to arrival, it was known to have low
thermal inertia,

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a characteristic of fine-grained materials like sand.

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An infrared spectrometer on OSIRIS-REx
confirmed this property,

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leading scientists to expect a predominantly
smooth surface.

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But the first close-up views of Bennu delivered
a major surprise.

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In exquisite detail, the mission’s cameras revealed
an unrelenting rock-scape,

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dominated by boulders.

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By combining these images from OSIRIS-REx with
its laser altimetry data,

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we can take a tour of Bennu’s remarkable terrain.

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The first stop is Simurgh Saxum.

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This prominent boulder defines the asteroid’s
prime meridian,

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and serves as the basis of its coordinate system.

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In Persian mythology, the Simurgh is a large and
benevolent bird,

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and the possessor of all knowledge

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Saxum is Latin for "stone."

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To the northeast lies the largest boulder on Bennu.

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Measuring over three-hundred feet in length,
Roc Saxum is a colossus,

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longer than a football field.

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It is also rich in a type of iron oxide called magnetite,

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which was used by mariners as an early form
of magnetic compass.

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In Arab folklore, the Roc is an enormous bird of prey
that can clasp elephants in its talons,

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as well as stranded sailors, like the hero Sinbad.

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♪♪♪

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Continuing northeast, over the equatorial ridge,
we arrive at Gargoyle Saxum.

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This striking boulder is among the darkest on Bennu,

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though it clutches a much brighter rock that is
about the size of a person.

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In Medieval legend, Gargoyles are dragon-like,
winged monsters that can breathe fire,

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and that guard cathedrals from evil spirits.

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Our next destination takes us far to the east.

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At the northern end of a small crater lies Ocypete Saxum,

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a comparatively bright boulder measuring about
thirty-three feet in diameter.

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Ocypete Saxum is located near one of three sites where
Bennu ejected small particles into space

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in early 2019, displaying its dynamic and evolving nature.

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In Greek mythology, Ocypete is one of the three harpies –
the half-maiden, half-bird

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personifications of storm winds, who would carry
evildoers away from the Earth.

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♪♪♪

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In the creation stories of ancient Egypt,

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the universe began as a formless, endless
expanse of water.

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From this primordial sea arose the
primordial mound: Benben.

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It was upon this rock that the god Atum settled,
in the form of the Bennu bird,

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and sent forth the call that shaped creation.

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The story of Benben hearkens to the mounds of
fertile silt that once emerged

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from the receding floodwaters of the Nile

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and it provides a fitting namesake for the tallest
boulder on Bennu.

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Protruding by over seventy feet,

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Benben Saxum is so tall that it was first detected
from Earth.

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Now, we can appreciate this monumental feature
in detail using data from OSIRIS-REx.

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♪♪♪

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The final stop on our tour is a cluster of
exceptionally bright boulders,

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scattered across the southern hemisphere.

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They bear the spectral fingerprint of pyroxene

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a mineral found in igneous rock, that is unlikely
to have formed on Bennu.

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These boulders most likely originated on the
large asteroid Vesta,

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and were delivered to Bennu’s parent body through
meteoroid impacts.

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♪♪♪

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Although it is small in small in size, asteroid Bennu
has proved to be a fascinating world…

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abundant in geographic features that have
defied our expectations.

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Thanks to OSIRIS-REx, we can now explore Bennu

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to uncover its composition…

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its evolution…

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and its ancient memories from the origins
of the solar system.

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♪♪♪