When the Apollo 11 astronauts left the surface of the Moon on July 21, 1969, they brought home samples of solar wind particles, lunar rocks and dirt, and a big helping of perspective.
Long before man journeyed to the moon and looked back at the tiny, fragile planet that houses humanity, lunar orbiters were sending back pictures of home.
The first image released from the Gravity Recovery and Climate
Experiment (GRACE), a joint NASA-German Aerospace Center mission,
graphically illustrates the sensitivity of the mission’s twin spacecraft
to changes in Earth’s gravity