Some Terms You Should Know: Finding the Planets
These are some terms you will come across in your lab class dealing with
When two objects have the same RA and Dec, they are in conjunction.
A planet is in conjunction with the sun will transit at local noon; this
is a bad time to view the planet.
Click here for a pictures: Inferior Planet or Superior Planet
When an inferior planet is at its greatest angular distance from the sun
in the sky as seen from Earth. Since inferior planets can never be
in opposition, this is the best time to view the planet. Click
here for a picture.
A planet whose orbit is smaller than that of the Earth. Mercury and
Venus are inferior planets.
When a planet or other body is directly opposite the sun in the sky as
see from Earth. A planet in opposition will transit at local midnight;
this is a good time to view the planet. Click
here for picture.
The apparent backward motion of a planet compared to other objects in the
A planet whose orbit is larger than that of the Earth. Mars, Jupiter,
Saturn, Uranus, Neptune, and Pluto are superior planets.
To cross the meridian. An object on the meridian will be at the highest
point it will reach in the sky.
to the definitions page
This page was last updated on 18 January 1998
and is © 1998 by Jim McDonald.