Hello, reader! Today the topic is....black holes! A black hole is a very dense region of space.  We're  not exactly sure how black holes are formed but scientists think there are at least two ways:

(1) A large star goes ka-boom (in other words, it dies).  How exactly does a star "die"?  Well, stars need fuel to exist.  They burn fuel constantly.  This burning counters the effect of gravity that's always present.  Eventually, the star runs out of fuel and there's nothing left to counter the force of gravity.  The gravity overwhelms the fuel that is pushing out and it compresses the star.  Sometimes the star simply collapses and sometimes the star implodes.  This forms a black hole.  A supernova is a normal size star the turned into a black hole.  A hypernova is a large star that turned into a black hole.  When a hypernova goes out, the first thing it does is release a gamma-ray burst that can obliterate anything it hits. 

(2) A bunch of matter in the center of the galaxy gets shoved together by gravity (gravity is a bully).  Eventually the matter gets so tight it collapses in on itself.  This forms a black hole.

Black holes are completely invisible.  Nothing can escape once its pulled in (oooh, scary).  They have an edge, though, called an event horizon. If you passed that edge, you'd be spaghettified, (turned into individual atoms, not turned into a tasty snack). 

To understand black holes, you need to know space-time. Our universe is measured in a fabric-like material called space-time.  Our standard measurements, length, width, and height are each a dimension.  But time is another, totally different dimension.  When you combine all four, you get space-time.  Let me show you. See, if you drop a ball onto stretchy fabric, you get a hole,....almost. That is gravity! And mass! But this tiny ball doesn't create a huge black hole. Now, let's imagine using an 8-pound dumbbell. It actually tears space-time like cheap rubber!  This creates a huge black hole in the fabric.  Get it?  Good.