Sarah T. Stewart: Where did the Moon come from? A new theory
Sarah T. Stewart specializes in the study of collisions in the solar system. Full bio
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led to a discovery
we think about the Earth and Moon.
is smash planets together.
using cannons like this one.
the extreme conditions
I can collide whole planets together
how to make the Earth and the Moon
from other planets.
of the Earth and Moon
struck the young Earth,
the debris disc around the planet.
so many things about the Moon,
from the Mars-sized planet,
are made from different materials.
are actually like identical twins.
in the isotopes of the elements.
have identical isotopes.
are made from the same materials.
and the Moon are twins.
from different materials,
have the same genetic relationship.
on the origin of the Moon,
reject the whole idea of the giant impact.
to explain the special relationship
there weren't any better ideas.
had even bigger flaws.
the giant impact theory.
that we try changing the spin
could mix more material
that part of the model.
the length of Earth's day?
giant impacts that could make the Moon.
faster-spinning giant impacts,
mixture of materials as the planet.
to explain the Moon.
that that's just not very likely.
is different from the planet,
making our Moon this way
for everyone to accept the idea
to Earth was an accident.
was still in trouble,
how to make the Moon.
when I realized my mistake.
from these fast-spinning giant impacts.
thinking about the Moon,
and partially vaporized
connected to the disc.
might be something really interesting.
with a separate disc around it.
was how we tested
going to look like a planet.
was making something completely new.
in front of me
to try and figure it out.
with the unknown?
a planet anymore?
of our old way of thinking,
throw away all of the data,
into the real world to test them,
with computer models
after most giant impacts,
that gets denser and denser with depth.
to figure out what was really going on
of astronomical object.
its rounded shape.
until it reaches a tipping point.
spreads into a disc.
of being a planet.
as it gets bigger and bigger;
between all of the material.
of a spheroidal shape.
of one of my simulations,
quickly from a previous giant impact.
would be recognizable
vaporizes the surface,
in just a few hours.
giant impacts make synestias,
don't live very long.
and turn back into planets.
like Earth were growing,
one or more times.
the problem of the origin of the Moon.
inside a huge, vaporous synestia.
inside the Earth
inside the synestia for years,
cooling and shrinking
for hundreds of years longer.
into two new bodies,
identical Earth and Moon.
throughout the universe.
by finding them in our imagination:
in the world around me?
by my own assumptions?
something truly amazing.
ABOUT THE SPEAKERSarah T. Stewart - Planetary scientist
Sarah T. Stewart specializes in the study of collisions in the solar system.
Why you should listen
Sarah T. Stewart has been a Professor in the Department of Earth and Planetary Sciences at UC Davis since 2014, following 11 years as a Professor at Harvard University. A planetary scientist and MacArthur Fellow, she specializes in the study of collisions in the solar system and directs the Shock Compression Laboratory, which uses light gas guns to study shock waves in planetary materials. Stewart is best known for proposing a new model for the origin of the Moon, and she is dedicated to public outreach in the planetary sciences.
Sarah T. Stewart | Speaker | TED.com