The DART mission is designed to
save Earth from an asteroid.
DART is our first planetary defence mission.
Defending against asteroids like this one.
Bennu.
We're bombarded by almost 50 thousand
kilograms of space rocks.
Every day.
Most are tiny and burn up in the atmosphere
as shooting stars.
But some bigger ones can cause real damage.
Like this meteor in Chelyabinsk, Russia,
in 2013, which exploded
with the power of 13 Hiroshima bombs.
And that was only 17 metres wide.
By comparison, the asteroid that killed the
dinosaurs was 10 to 15 kilometres wide.
And now there is another asteroid on its way.
Bennu is about 0.5 kilometres wide,
about as wide as the Empire State Building
is tall.
Between the years 2175 and 2199,
there is a 1 in 2700 chance of Bennu
impacting Earth.
Doesn't sound like much of a risk,
but if it does hit,
it will have the power of
80,000 Hiroshima bombs.
But don't worry.
NASA and the European Space Agency are on it.
Enter DART.
The Double Asteroid Redirection Test.
Developed and led for NASA by Johns Hopkins
University Applied Physics Laboratory,
it does what it says on the tin, really.
At least that's the aim.
DART is a demonstration of the kinetic impact
technique.
Just slamming a spacecraft into the
asteroid.
Brilliant.
I'm Lindley Johnson, and I am NASA's
first ever planetary defence officer.
This mission will demonstrate that
humankind doesn't have to worry about
going the way of the dinosaurs.
Why double?
It is called the Double Asteroid
Redirection Test because we are targeting a
binary asteroid system called Didymos,
which means twins, and impacting the Moon
to change that moon's orbit around the
larger asteroid.
The impact effects of an asteroid the size of
Dimorphos, the moon of Didymos,
160 metres or so in size,
the size of a small football stadium,
would be an area of a small
United States or a European nation.
So it's important that we be able to
protect life on Earth with this capability.
DART is set to hit Didymos in Autumn 2022.
We'll be able to measure some of
the impact from Earth,
but another spacecraft is heading that way.
The European Space Agency's Hera will arrive
around four years later to assess the outcome
of DART's mission.
But why go to so much trouble when
Didymos isn't even at risk of hitting the
Earth?
Because Didymos isn't the only thing out there.
There are over 20,000 asteroids
close to the Earth, of which 1200
are considered high risk.
Thankfully, people like Richard Kowalski
scour the night sky to find asteroids
before they find us.
They're known as the asteroid hunters.
As you can see on this screen is the sequence
of four images that came from the telescope.
These objects around the screen are not
moving, so I know that they're stars,
but this object in the centre is moving,
and thus we know that it's an asteroid.
The importance of surveying for near-Earth
asteroids is asteroid impact on the Earth
is truly the only natural disaster that
we can actually predict before it happens.
The Earth has been hit in the past and
will be hit again in the future.
What we'd like to do is to be able to
discover these objects before they hit the
Earth.
Observations collected are all sent to the
Minor Planet Centre, and if they are
asteroids that could come near the Earth and
and be a potential impact hazard,
that information is sent to the Planetary
Defence Coordination Office at NASA.
If an asteroid is a more immediate threat
of impact,
I actually get a text notification on my
smartphone.
At NASA we're kind of the Uber asteroid hunters
maybe is what you could say.
So what would happen if an asteroid did
hit Earth?
Well, we all know impacts leave
craters, but what else happens?
Because it's not just the collision itself
that would cause devastation.
So for this experiment, we're going to fire
this tiny quarter inch aluminium sphere
at very high speeds up around
5 kilometres per second and then we'll see
what type of crater it produces.
So we use sand because it records the
shock effects very clearly.
Pete Schultz uses super high-speed cameras
to capture every detail of the impact
and aftermath.
And high voltage, and paddle is in,
warning lights, and rolling.
The ball travels 15 times faster than the
speed of sound and, like some asteroids
would, incinerates on impact.
Oh, perfect, perfect, perfect.
Now we're seeing the fireball come in,
it's brighter than the sun and then kapow!
It hits the surface.
Jeez, this whole region down range
would have been incinerated.
It would have been incinerated just by this
plasma, this exploding vapour plume
engulfing everything.
There would have been winds that would have
been going so fast it could pick up houses
and spread them hundreds of kilometres away.
This would have been Armageddon.
So all eyes are on the DART mission.
And there are a couple of other asteroid
deflection ideas floating around too.
Some of them are wild.
Here are some of the top ones.
One. Nuke it.
Very Hollywood and probably the first thing
you thought of too.
Great in theory, but could result in
radioactive debris raining from the sky.
Not ideal.
Two. Gravity tractor.
Sounds very space farming, doesn't it?
The idea here is to fly a device next to an
asteroid so it slowly pulls it away from the
Earth's path.
This offers a lot of control,
but it might not be effective for anything
over 500 metres in diameter.
Three. Paintballs.
Yep, you heard right.
Paintballs.
Personally, my favourite suggestion.
First, the act of shooting the
asteroid would deflect it,
and also using white reflective paint
means that the force of the Sun's photons
would theoretically push the asteroid
even further off course.
The downside?
It'd need about 20 years' notice for it to work.
So we've got paintballs, tractors and nukes.
Which might all seem like crazy ideas,
but they're serious contenders.
For now, though, it's all eyes on DART
and its mission to save the world.