Gravity is the powerful force that glues our universe together.
Gravity helped form our solar system, the planets, and the
stars. It holds the planets in orbit around the Sun, and moons
in orbit around the planets. The gravitational pull of the Sun
and Moon creates the tides on Earth. Far beyond our solar
system, the irresistible force of gravity is collapsing stellar
cores into amazing - and bizarre - objects in our universe--
neutron stars and black holes. |Pushing the Moon Away| Our Moon
is moving farther away from Earth! The energy transferred from
gravitational tides is causing the Moon to move away at almost 4
cm a year, and slowing the Earth's rotation! This fundamental
force of gravity will help scientists model the interior of our
Moon, Earth, and other planets, and measure the masses of
distant stars and galaxies. NASA's GRAIL mission is studying the
Moon's gravitational field, which will give scientists a better
picture of the lunar interior. The GRACE mission is still making
detailed measurements o