A rogue star is headed
straight for our Sun.
If these two stars slam into each other,
it could spell the end
of all life on our planet.
As the name would suggest,
rogue stars drift through space.
They don't belong to any particular galaxy.
Or if they once did,
they've been ejected from their homes
at some point
by supernovas
or two galaxies ramming into each other.
Whatever it is that sends these stars
hurtling away from the gravitational
pull of their original galaxies,
it fires them off at very high speeds.
In order to break free
of our own Milky Way galaxy,
a star would need to move
as fast as 550 km/s (340 mi/s).
Luckily, our Sun is only moving
at a mere 200 km/s (124 mi/s).
Not nearly fast enough to become rogue.
But these wandering stars
aren't all that uncommon.
They may even account for as many
as half of the
200 billion trillion stars in the Universe.
And one of them could be headed
toward our Sun right now.
Meet Gliese 710.
This rogue dwarf star is on a trajectory
that would bring it close
to our Solar System
in around 1.3 million years.
When Gliese 710
eventually reaches us,
it would enter the outermost section
of our Solar System,
the Oort Cloud,
at a speed of about 51,500 km/h (32,000 mph).
It could send the icy bodies out there
flying in different directions.
Maybe even right toward Earth.
Once it has reached Neptune,
the countdown to the epic collision
would begin.
T minus 10 years till the impact
with the Sun.
At this point,
you'd better just plan
to live your best life
while preparing
for the upcoming apocalypse.
The gravitational pull of Gliese 710
would destabilize the orbits
of our planetary neighbors,
nudging them left and right.
This could go as far as pushing Earth
out of the habitable zone.
Or it could turn us into a rogue planet
after unceremoniously being catapulted
out of the Solar System.
After ten years,
it would finally be getting close
to collision time.
As each day passes,
things are only going to get worse.
One possibility
is that the Sun and Gliese 710
would merge into a red nova.
This would result in a violent explosion
that would unleash
nearly half a million times more light
than what the Sun does right now.
Given the amount of time
light takes to travel
from the Sun to the Earth,
you would be
blissfully unaware
of this destructive explosion
for 8 minutes.
But the moment you do find out
all that light
would likely blind you in a millisecond.
And then immediately fry you on the spot.
That's because directly behind
this blinding light
would be super hot gas.
This wave of heat
could be powerful enough to wipe out
nearly everything in its path.
Bye bye Mercury,
Venus and yeah, Earth too.
Our atmosphere and oceans
would be completely blasted away.
This would leave our planet
as nothing more than a barren rock.
The explosion would also have created
massive amounts
of high energetic neutrinos.
These would be able to
boil you from the inside out.
Earth would also be shrouded in
lethal levels of UV and gamma radiation.
Even if you somehow managed
to survive the explosion,
you wouldn't last long
from the harmful effects
of all this radiation.
You'd have damage to your eyes,
skin and even DNA.
Now, if an alien species was watching this
all unfold from a distant galaxy
with an incredibly powerful telescope,
they'd see a single bright star
surrounded by an excess
of reddish-colored gas.
and the infrared light
left behind from the explosion
would be visible for a long time after.
But that wouldn't be the only way
all this could possibly go down.
There is a possibility
there could be a more peaceful alternative.
Yeah, if the two stars are moving
a bit slower relative to each other,
they could end up merging
into one massive new star
as they orbit each other.
Our Sun would strip mass
from its smaller companion, Gliese 710,
and swallow it in a process
known as stellar cannibalism.
Then this extremely hot and bright star
would be called a blue straggler.
Though it may sound
many times more peaceful,
this option would still likely spell out
the end of life on Earth.
With our Sun now a massive blue star,
the habitable zone
of our Solar System
would be pushed further away.
What else would happen
if our Sun became a blue star?
Well, that’s a story for another WHAT IF.