An instrument used for measuring the water vapor content of the air.

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Named to honor the first Roman emperor (and grandnephew of Julius Caesar), Augustus Caesar (63B.C.-A.D.14).


Fear of lightning/thunder

Evening star

A planet that is above the western horizon at sunset and less than 180° east of the Sun in right ascension.

Lenticular Cloud

Lenticular clouds are only seen around mountains. These strange clouds are easy to spot, because they look like flying saucers or a stack of pancakes. Their most interesting characteristic is that they don't move. Winds blow right through them, while other clouds are swept away.


The point in a planet’s orbit that is closest to the Sun.


Named to honor Roman dictator Julius Caesar (100-44B.C.). In 46 B.C., Julius Caesar, with the help of Sosigenes, developed the Julian calendar, the precursor to the Gregorian calendar we use today.


The apparent annual path of the Sun around the celestial sphere. The plane of the ecliptic is tipped 231⁄2° from the celestial equator.

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