Gram-negative ((of bacteria) being of or relating to a bacterium that does not retain the violet stain used in Gram's method). Hyponyms (each of the following is a kind of bacteria): acidophil; acidophile (an organism that thrives in a relatively acid environment).
Gravity from the Sun reaches throughout the solar system and beyond, keeping the planets in their orbits. Gravity from Earth keeps the Moon and human-made satellites in orbit. It is possible to far away from a planet or star and feel less gravity, because gravity decreases with distance.But that doesn't account for the weightless feeling that astronauts experience in space.ravity from the Sun reaches throughout the solar system and beyond, keeping the planets in their orbits. Gravity from Earth keeps the Moon and human-made satellites in orbit. It is possible to far away from a planet or star and feel less gravity, because gravity decreases with distance.
Sometimes rings will have shepherd moons, small moons that orbit near the inner or outer edges of rings or within gaps in the rings. The gravity of shepherd moons serves to maintain a sharply defined edge to the ring; material that drifts closer to the shepherd moon's orbit is either deflected back into the body of the ring, ejected from the system, or accreted onto the moon itself.