Index :

A - B - C - D - E - F - G - H - I - J - K - L - M - N - O - P - Q - R - S - T - U - V - W - X - Y - Z .

eccentric

Noncircular; elliptical (applied to an orbit).

eccentricity

A value that defines the shape of an ellipse or planetary orbit; the ratio of the distance between the foci and the major axis.

eclipse

The cutting off of light from one celestial body by another.

ecliptic

The plane of Earth's orbit about the Sun

eddy

A current that goes against the main current, it causes a whirling motion to occur (much like a whirlpool).

effusive eruption

A relative quiet volcanic eruption which puts out basaltic lava that moves at about the speed one walks. The lava is fluid in nature. The eruptions at the Kilauea volcano on the island of Hawaii are effusive

Einstein, Albert 1879-1955

German-American physicist. Einstein developed the Special and General Theories of Relativity, which along with Quantum Mechanics, forms the foundation of modern physics.

ejecta

Material such as glass and fragmented rock thrown out of an impact crater during its formation.

electromagnetic spectra

The entire spectrum of all kinds of electric, magnetic, and visible radiation as well as waves of longer wavelengths.

ellipse

An oval. Johannes Kepler first discovered that the orbits of the planets are ellipses, not circles; he based his discovery on the careful observations of Tycho Brahe.

en echelon fissures

Fissures that are parallel in trend to each other, but offset to either the left or right.

eolian

Related to wind deposits and associated effects.

epicycle

Small circles that the Sun, planets, and moon where thought to follow while they traveled in their much larger orbits around the fixed Earth.

equinox

The time when the Sun crosses the plane of the Earth's equator, making night and day approximately equal lengths all over the Earth. This occurs on or about March 21 (vernal or spring equinox) and September 22 (autumnal equinox).

eruption

The ejection of volcanic materials (lavas, pyroclasts and volcanic gases) onto the surface, either from a central vent, a fissure or a group of fissures.

EVA

It stands for extra vehiclular activity, in other words a spacewalk.

explosive eruption

A dramatic volcanic eruption which throws debris high into the air for hundreds of miles. The lava is low in silicate and can be very dangerous for people near by. An example is Mount St. Helens in 1980.

HOME