Astro Glossary

Genesis probe

A spacecraft that collected a sample of solar wind and returned it to Earth for study. Its parachute failed during its descent, destroying its sample container. Scientists were able to collect the contents, however, and are working to extract bits of the solar wind from the debris.

Geology and Archaeology

Giant Galaxies

Goddard, Robert

A scientist and engineer who pioneered much of the basic technology of modern rockets. In 1926, he launched the first liquid-fueled rocket. Over the years, Goddard developed the basic technology for rocket engines, ways to keep a rocket stable, and many other technologies that are still in use today. He was awarded more than 200 patents, many of them after his death in 1945. Goddard was reclusive, however, so much of his work was overlooked at the time and was later duplicated by other engineers.

Grades 3-5 (Ages 8-10)

Grades 6-8 (Ages 11-13)

Grades PreK-3 (Ages 3-8)

Gravitational Waves

Ripples in space-time created by the stretching and squeezing effects of massive objects, notably supernovae, binary black holes, and binary neutron stars. Gravity waves are transverse waves, meaning that they stretch and squeeze space-time in directions perpendicular to the wave’s motion. Einstein’s Theory of General Relativity predicts the existence of gravity waves, but they have not yet been detected.

Gravity

The most feeble of the four fundamental forces in the universe that affect all matter. The magnitude of gravitational attraction depends directly on mass and inversely on distance squared. For instance, the gravitational attraction between you and Earth is much greater than that between you and the Sun, even though the Sun is 333,000 times more massive than Earth. The distance separating you from the Sun weakens the mutual gravitational attraction, so as you stand on Earth’s surface, Earth’s gravitational pull on you is 1,650 times greater than the Sun’s.

Greek and Roman Mythology