Space Place... in a Snap!
What is a black hole?
Space is a 
pretty dark place.
Even so, some areas are darker than others.
Nothing is darker than a black hole.
A black hole is an area of such immense gravity
that nothing—not even light—can escape
from it.
Black holes form at the end of some stars’
lives.
The energy that held the star together disappears
and it collapses in on itself producing a
magnificent explosion.
Here’s where things get crazy.
All of that material left over from the explosion,
many times the mass of our Sun, falls into
an infinitely small point.
Black holes can form in many ways though,
and large black holes can have tens to millions
of times the mass of our sun trapped in a
point smaller than the tip of a pin!
Some black holes trap more and more material
as their mass increases.
The point where all that mass is trapped is
called a singularity.
It may be infinitely small, but its influence
is enormous.
Imagine a circle with a singularity in the
middle.
The gravity on the inside of the circle is
so strong that nothing can escape—it sucks
in everything, even light.
That's why it's black!
This circle is known as the event horizon.
An event horizon is probably what you are
thinking of when you think of a black hole.
What would happen, you might wonder, if we
took a spacecraft near a black hole’s event
horizon?
The answer—spaghettification!
That’s the technical term, at least.
As our spacecraft approaches it, the gravity
will be so much stronger on the side closer
to the black hole than at the other side that
it will get completely stretched out like
a piece of spaghetti.
Try as you may, you would be hard-pressed
to find anything weirder or cooler than a
black hole…
Presented by NASA Space Place.
For a transcript of this video and a fun downloadable poster
visit the Space Place.
