Nearly a century ago, Edwin Hubble, an American Astronomer, made the surprising observation that galaxies are moving apart, and that galaxies farther away from us are moving faster than nearby galaxies. With this, he showed us that the Universe is expanding. Towards the end of the last century, scientists discovered something even more surprising. When they more carefully studied how fast nearer and farther galaxies are moving away from us, they found that the Universe is not just expanding, but that the rate of expansion is increasing.