Astronomical Dictionary Page #9

Venus

Planet second in order from the sun. In Roman mythology, goddess of love (Greek name, Aphrodite)....

Vent

An opening or fissure in a planet's surface through which volcanic material erupts....

Viscosity

A measure of resistance to flow....

Volcanic rock

Rock formed by eruption onto a planet's surface....

White Dwarf

A Star whose nuclear energy sources has been exhausted, except in the outermost layers. About 14% ...

Worm Hole

A hypothetical shortcut through the space time continuum. ...

Zenith

The point on the celestial sphere directly above an observer, or the highest point in the sky reache...

Zenithal Hourly Rate

It is the number of meteors per hour, for a particular stream, that is estimated will be seen under ...

Zodiac

A circular band extending about 9?° on either side of the Ecliptic; thus, an 18?°-wide band. The...

Zodiacal Light

A faint glow from light scattered off interplanetary dust in the plane of the ecliptic. Best seen at...