Astronomical Dictionary on Letter #E

Eccentricity

Literally, not circular. The eccentricity of an ellipse (orbit) is the ratio of the distance between...

Eclipse

A chance alignment between the Sun, or any other celestial object, and two other celestial objects i...

Ecliptic

The great circle formed by the intersection of the plane of the Ecliptic with the Celestial Sph...

Elongation

The angular distance of an interior planet from the Sun, as seen from the Earth. The term Greatest E...

Equatorial Mount

A telescope mount so designed so that the two axes, which support it, are aligned, one to the polar ...

Equinox

Literally, the time of equal day and night. This is the time when the Sun crosses the celestial equa...

Europa

In Greek mythology, a mistress of Zeus to whom he appeared as a gentle white heifer. Zeus persuaded ...

Escarpment

A long, more or less continuous cliff or relatively steep slope facing in one general direction, pro...

Encke

Johann Franz Encke (1791-1865) German astronomer at the Seeberg Observatory, Switzerland. Determined...

Enceladus

In Greek and Roman mythology, a giant, son of Titan and Gaea. Buried by an angry Zeus under Mount Et...

Ejecta

Material thrown out of a volcano or impact crater....

Eistla

In Norse mythology, a giantess....