Glossary for the Solar system and the Earth

Dark energy: A theoretical form of energy postulated to act in opposition to gravity and to occupy the entire universe, accounting for most of the energy in it and causing its expansion to accelerate.

Magnetic field: A force field that is created by moving electric charges and magnetic dipoles, and exerts a force on other nearby moving charges and magnetic dipoles.

Penumbra: The partially shaded outer region of the shadow cast by an opaque object.

Asteroids: Small rocky celestial bodies that revolve around the Sun, like other planets.

Standard time: A uniform time for places in approximately the same longitude, established in a country or region by law or custom.

Galactic movement: This is the movement of the earth with the sun and the rest of the solar system in an orbit around the centre of the MilkyWay Galaxy

Equinox: Time when the apparent movement of the sun is overhead the equator.

Gibbous: Third quarter of moon’s phase is known as Gibbous.