A typical neuron makes about ten thousand connections to neighboring neurons. Given the billions of neurons, this means there are as many connections in a single cubic centimeter of brain tissue as there are stars in the Milky Way galaxy.

Your brain is built of cells called neurons and glia - hundreds of billions of them. Each one of these cells is as complicated as a city.

The dynamics within the core of this neighboring galaxy may be more common than we think. Our own Milky Way apparently has even younger stars close to its own black hole. It seems unlikely that only the closest two big galaxies should have this odd activity. So this behavior may not be the exception but the rule. And we have found other galaxies that have a double nucleus.

There may be aliens in our Milky Way galaxy, and there are billions of other galaxies. The probability is almost certain that there is life somewhere in space.

Some of the stars in this Milky Way companion have been seen with telescopes for centuries. But because the galaxy is so close, its stars are spread over a huge swath of the sky, and they always used to be lost in the sea of more numerous Milky Way stars. This galaxy is so big, we couldn't see it before.

A broad and ample road, whose dust is gold,
And pavement stars—as starts to thee appear
Soon in the galaxy, that milky way
Which mightly as a circling zone thou seest
Powder'd wiht stars.