You know what I'm really glad exists?
Like, besides my family, Hot Pockets and They Might Be Giants?
NASA's Near-Earth Object Program.
The NEO collects data from astronomers around the world
who track nearby asteroids and calculate the asteroids' paths
and ranks them by risk.
So we don't have to!
Threats are ranked from 0 to 10, zero meaning don't bother
worrying and 10 meaning don't bother getting out of bed.
The highest rating ever assigned was 4, when asteroid 2004 MN4,
aka Apophis, was given a 1.8% chance of hitting the earth in 2029.
But to show you how quickly things can change
in the asteroid-tracking business, once astronomers projected
all of the other bodies that Apophis would interact with
in its travels, the NEO realized that the probability
of impact was more like 0.00074%.
So, it's ok.
So like almost all of the thousands of asteroids
that NEO tracks, Apophis is now a zero.
Yeah, I said almost.
There's still 2007 VK184.
It's about 130 meters across.
Plenty big for it to burn through our atmosphere
and have enough left to wreak some serious havoc.
It's actually swinging by in 2014, but that's not the problem.
NEO says that when it returns on June 3, 2048,
its chances are 1 in 1,820 that it's going to punch the earth
right in the face.
Still, that's just a 0.055% chance.
Then there's 2011 AG5.
It's slightly bigger about 140 meters across.
And on February 5, 2040, NEO figures,
the odds of a collision are 1 in 500, or a 0.2% chance.
The good news is that AG5 comes by every few years,
so we've got a lot of opportunities to observe its path more
and refine our projections.
In fact, when it comes by in 2023, we already know the exact path
it has to take if it's going to hit us the next time around.
Astrophysicists call this a keyhole.
It's the area through which the object would have to travel
for the Earth's gravitational pull to sort of pull it into
a collision course when it returns in 2040.
In the case of AG5, the keyhole is only 360 kilometers wide.
Which seems kind of big, but not when you're space.
AG5 finding its way through that narrow of a keyhole seems about
as likely as bouncing a beer pong ball in New York
and having it land in a solo cup in London.
Which is why both of these asteroids are still ranked at a lowly 1.
But there is one asteroid of interest that's not on NEO's lists,
only because its possible threat is centuries away.
Asteroid 1950DA has been freaking people out for decades
because it's more than a kilometer across.
Big enough to cause planetwide, extinction-event-level destruction.
And it also has the highest impact probability so far.
At worst, 1 in 300 or 0.33%.
Thing is, our rendezvous with 1950DA won't happen
until March 16, 2880.
And by then, my descendants and your descendants
and the descendants of They Might Be Giants
will probably be enjoying Hot Pockets on colonies far away.
So either way it'll be OK!
Thank you for watching this episode of SciShow.
I'm so glad that I could help deliver you the good news:
That we're not all about to die as the result of an asteroid impact.
If you want to know more you should subscribe,
and if you have questions, leave them in the comments below,
or contact us on Facebook or Twitter, and we'll see you next time.