The cosmos can be a dangerous place.
Take black holes for example.
They're some of the most
violent objects in our universe,
powerful enough to rip
entire stars to pieces.
Their secret weapon is gravity.
You see, the more mass you
can shrink into a small space,
the stronger your gravitational
force will become.
To make Earth into a
black hole, for instance,
you'd have to shrink it to
less than an inch across.
But real black holes are
much larger than that
and pack way more mass than Earth.
Here's just how big black
holes can really get.
There are three common
types of black holes.
The smallest are stellar black holes,
which form after a giant star explodes
and collapses in on itself, like this one,
which measures about 40 miles across,
roughly three times the
length of Manhattan.
But in that small space
is enough mass to equal 11 of our suns.
In another galaxy called M33,
there's a black hole
that is 58 miles across
and packs as much mass
as 15.7 suns inside.
Up next are the
intermediate-mass black holes,
like this one.
At 1,460 miles across,
it's nearly large enough to
stretch from Florida to Maine,
and according to some calculations,
contains the mass of 400 suns.
At this point,
black holes start to get
pretty big compared to Earth,
but it's still nothing
when you consider the
sheer mass they carry.
Take this black hole for example.
It's nearly twice the size of Jupiter,
spanning a region about
172,000 miles wide,
but inside is as much mass as 47,000 suns.
But these black holes are nothing
compared to supermassive black holes,
like Sagittarius A*,
which lives at the center
of our Milky Way galaxy.
It covers a region about 14.6
million miles in diameter.
That's roughly 168 Jupiters across,
and inside is the same amount of mass
as 4 million suns combined.
Now, that may sound big,
but Sagittarius A* is small
compared to other
supermassive black holes.
Take the one at the
center of our neighbor,
the Andromeda galaxy,
which has a diameter of 516 million miles,
larger than Jupiter's orbit,
and contains enough mass
to equal that of 140 million suns.
We're finally getting
to some of the largest
black holes in the universe,
and yet, we haven't reached one
that surpasses the size
of our solar system.
So let's look at the
supermassive black hole
at the center of the Sombrero galaxy.
It measures 2 billion miles across,
so it would stretch
further than Uranus' orbit,
and it has about the same
mass as 660 million suns.
And the supermassive black hole
at the center of Messier 87
is so huge that astronomers could see it
from 55 million light-years away.
It's 24 billion miles across
and contains the same mass as
6 1/2 billion suns.
But this supermassive black
hole, as large as it is,
could still fit within our solar system
with plenty of room to spare.
So we have to look at
one of the most massive
of all supermassive black holes.
It has a diameter of
about 78 billion miles.
For perspective, that's about 40% the size
of our solar system,
according to some estimates.
And it's estimated to be
about 21 billion times
the mass of our sun.
So there you have it,
black holes can be
millions of times larger
than suns and planets
or as small as a city.
It all depends on how much mass is inside.
Turns out, when it comes to the cosmos,
size isn't the only thing that matters.
