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There are still lots of things about space
that we may never be able to answer,
like is time travel possible?
Or are aliens living somewhere else in the Milky Way?
But there is one thing I believe about space:
Space is trying to kill me.
Space isn't out to get me personally.
It's also trying to kill you and everybody else.
Think about it.
Space doesn't naturally have what we need to survive
when we travel there:
no air,
it's too hot
or too cold,
no ozone to protect us from those nasty UV rays, either.
This all sounds bad,
but what can space really do to me
if I stay on Earth?
What we need to understand is that objects in space
can cause people to think their days are numbered,
even when there are events on Earth
that can hurt or kill us
before something from space does.
So, what are the odds that one of these objects
will really affect Earth
and you
and me
in our lifetime?
Well, we can take what we know about the universe
to try and figure that out.
You might have heard stories
about asteroids hitting the Earth.
That would be pretty bad.
Scientists think asteroids might have killed off
most of the dinosaurs.
Sounds like something we should worry about, right?
Well, astronomers can now watch asteroids in space
and see them coming using complex computer models
to predict the deadly rock's path.
For a while, the reported odds
that asteroid Apophis would strike Earth in 2036
were once 1 in 625.
But, after updating their data,
astronomers now say the chances are extremely low.
Okay, what about the sun?
Hollywood movies like to pick on our sun
by showing Earth destroyed by solar flares
or the sun dying out,
which would cause Earth to freeze.
Astronomers predict our sun contains enough gas
to make energy for another 3 to 5 billion years.
So, in 3 to 5 billion years,
if people still exist on Earth,
they'll have to deal with that.
But today, well, we're safe.
Sometimes the sun does shoot flares at Earth,
but the magnetic fields surrounding our planet
blocks most of that radiation.
The radiation that does get through
creates things like the Aurora Borealis.
Gigantic solar flares can mess with our satellites
and electrical equipment,
but the chances of it killing you are pretty slim.
Okay, what about that supermassive black hole
in the middle of our galaxy?
What happens to Earth,
and us,
when it pulls us in?
After all, it is supermassive.
Nope, not going to happen.
That's one big object that can't bother us.
How can we be so sure?
Our solar system is on the edge of the Milky Way
while the nearest supermassive black hole
is about 26,000 light years from Earth.
That means we aren't on that black hole's menu.
So, you still think space objects are trying to kill you
even after what I've told you so far?
I think I've even convinced myself
that odds are really good
that space and the objects up there
won't kill me after all.
But I'll probably keep looking up
just to make sure nothing is headed my way.