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ezscienceindex

Earth: the planet in space
Earth: inside the planet
Earth's atmosphere *includes images
Earthquakes **includes animations

Eccentric orbit: Elliptical or noncircular. (Explore How Planets Orbit.)

Eclipses **includes animations

Electron: Negatively charged particles of energy that orbit the shell or shells of an atom.

El Niño & La Niña

Elongation: Point of greatest separation of the inner planets from the Sun, as viewed from Earth. More.

ENSO: El Niño-Southern Oscillation. (See El Niño & La Niña)

Epicenter: Point on the surface directly above the focus of an earthquake.

Equinox autumnal and vernal

Europa: One of four Galilean moons of Jupiter.

Evaporation **includes animations

Exobiology

Explosive deepening: A decrease in the minimum sea-level pressure of a tropical cyclone of 2.5 millibars per hour for at least 12 hours or 5 Mb/hr for at least six hours.

Extratropical cyclone: A cyclone that has lost its "tropical" characteristics. The term implies both poleward movement of the cyclone and the conversion of the cyclone's primary energy source from the release of latent heat of condensation to baroclinic (the temperature contrast between warm and cold air masses) processes. It is important to note that cyclones can become extratropical and still retain winds of hurricane or tropical storm force.

Eyewall: An organized band of clouds immediately surrounding the eye of a tropical cyclone (including hurricanes) where the winds are the strongest. Eye wall and wall cloud are used synonymously.

Eye: The relatively calm center of the tropical cyclone (including hurricanes) that is more than one half surrounded by wall cloud. Characterized by calm winds and often clear conditions.