Mercury

It is a interior planet.
Mercury is the closest planet to the Sun and the smallest planet in the solar sistem, without counting the nano planets.

It takes 88 days to orbit the Sun and 176 to rotate on its axis.

It is like our satelite, the Moon, it has a lot of craters on it. You can see them so much, because their atmosphere is very weak.

It has no satellites.

The Moon Was Born

About 4.4 billion years ago a object the size of Mars crashed  into our planet. It took big peaces of the Earth
out of it and in a hundred years one of the peaces formed into the spherical rock we call Moon.

Supernoves

Stars dont live for ever, but they lives for a long time.Some stars when they die the supernova occurs. It is a giant explotion that killes everything around it.

The nearast star to us is Alpha Centauri and it is 4.3 light years away. If it exploded would we have 4.3 years beofore we died? No, we woudn't. We would die at the same time.
A supernova will occur once every 200-300 years in each galaxie.