"Timbo" wrote in message
...
Hi all,

I'm a complete newbie with astronomy, and have an issue in relation to my
new Celestron Firstscope 76 EQ - basically, I cannot get a good view of
Mars, or any other planet / object for that matter..

For example I can focus on Mars, but what is a couple of millimetres in
the
sky, is only approximately 'double' the size when viewed through the
eyepiece - no detail at all. The brochure from celestron states that the
Firstscope 76 (tabletop) 'is small but powerful so you can study Saturn
and
it's rings, Jupiter and it's surface details and moons...'etc - are you
supposed to have bought optional extras before you can see these things or
am I simply not doing something right here...any help appreciated..!!

Thanks
Tim.
The first thing that worries me, is that you see Mars as having any 'size'
at all without the scope. Mars is moving away fast, and now, covers about
the same angle, as 'cent', over 200 yards away. This is below the
'resolution' of the human eye (even at it's best), and it is now a 'point'
object. This possibly suggests that your eyes have a significant aberration,
and you are seeing the object as 'extended' by this aberration... This may
be distorting your perception of what the scope is doing.
You refer to Mars as being a 'couple of millimeters', then "approximately
'double' the size when viewed through the eyepiece". Assuming you have the
shorter focal length eyepiece fitted (which gives about 70*), Mars should
appear the same size as an object about 4mm across, at a distance of just
over a yard from you. This is still _very_ small, and would tally with what
you are seeing, but _is_ large enough, that some faint awareness of surface
'texture', may just about be visible if you are careful. The scope, is
capable of exceeding many of the instruments that the first astronomers
used, but it cannot perform miracles. A few weeks ago, when Mars was at it's
closest, it would have been about the size of a 'cent' a yard away.
Definately large enough to see some detail.
A shorter focal length eyepiece, or a Barlow lens, will allow higher
magnification to be used, and will show a bit more on the planets.
Both Jupiter, and Saturn, should be well visible (early morning objects at
present), Jupiter at it's best, with your higher magnification eyepiece,
will be enlarged to being just about the same size as the full Moon. Plenty
large enough to see a lot of detail (it will be slightly smaller than this
at present).
Actually seeing detail on planets, may not be as easy as you expect. It
takes a while for your eyes to get 'used' to the bright object against the
dark background, and to see the often 'transient' moments of good viewing,
as the atmosphere shifts. Getting good focus is vital - focus on a star
nearby first.

Best Wishes