| Planispheres
are not difficult to use once you have used one a few times. the numbers
around the edge can be very of-putting but are in fact quite easy
to read. The Planisphere is a good tool to have to find your way around
the sky and it's inexpensive. If you are going to buy one, make sure
it is suitable for your latitude and hemisphere. To use your planisphere,
you firstly need to set the date. So if it is the 1st May, locate
the date around the edge- don't worry if the dates don't run consecutively.
Now turn the top layer until it comes round to the current time e.g.
6 o' clock. Now decide what you would like to look at. On the reverse,
there are sometimes tables for the major planets. Use it like a calendar
and read the number e.g. "100". This number stands for "100"
degrees. Now work your way around the edge of the planisphere and
locate "100" degrees. Line up a straight edge (a ruler will
do) through the center of the planbisphere to the "100"
degrees mark. If the area s covered up, this means the object is not
yet in view. If it is not covered up, then you should mark the point
(maybe with a small sticker) where the straight edge crosses the ecliptic
- represented as a long dashed line. This line is the path that the
sun and moon follow across the sky an most planets also follow this
path within a few centimeters above or below it on the Planisphere
(The planets only appear to follow the same path because of the Earths
tilt and rotation and hence their position will vary week to week,
sometimes not being visible at all - Note - They will not follow the
same path every night of the year). Now you should look up at the
night sky and search for a prominent constellation - Orion for example.
Now hold the Planisphere directly above your head and match the constellation
in the sky with that on the Planisphere. Now you should be able to
find your selected planet, which will typically look like a bright
star like Jupiter and Saturn do. When I first began I pointed the
scope to the brightest stars but it was hit and miss. A Planisphere
is the best way to go. Your planisphere may also show different galaxies
and nebula along with the constellations, so have a good look at it. |
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