How Old Is the Universe?

You already know that the Universe grew from a tiny point after the Big Bang. But when did it happen, and how much time has passed since then?

Scientists searched for the answer for a long time. They studied the movement of stars and galaxies and finally worked it out.

The Universe is almost 14 billion years old. That is 14,000,000,000 years—look at all those zeros! It is difficult to imagine, but let’s try.

Let’s Compare It with Something Familiar

Our planet Earth formed about four billion years ago (4,000,000,000). It is roughly three times younger than the Universe.

The first humans appeared only about three hundred thousand years ago (300,000).

So the Universe is very old, but it has not stood still.

The Universe Is Still Growing!

Yes—even as you read this, galaxies are moving farther apart, as though an enormous balloon were still being inflated.

Perhaps the Universe will expand forever. Or perhaps one day it will contract again and, billions of years from now, return to a tiny point before being born anew.

Scientists still debate this. What do you think?