Observing log: A tale of two moons

Last night I brought the SCT out for the first time in over a month. I was in Vegas w/o a telescope for a number of weeks and needed to get my observing fix.

I first started out with the scorn of Deep Sky observers and our nearest neighbor, the Moon. Being nearly full, I needed my filter to cut down on some of the glare. Here is a quick review of some of the features I observed (attempts to verified features using Virtual Moon Atlas)

8" SCT w/9.4 PL, 12.5 PL, and 26MM PL

Using the 26mm which gives 73x, it frames the Moon perfectly in the eyepiece. I use this mag just to scan the whole surface, the mare, larger craters etc. Soon saw some interesting area's that I wanted to check out further near the limb.

Using the 12.5mm which gives 163x, I came across a crater near the limb that had a distinct "V" shaped "valley" on the crater wall. I think I have it identified it as Euctemon, if you are an avid Lunar observing please let me know if this sounds correct. I referenced Virtual Moon Atlas, but unfortunately I should have noted its position on paper at the scope and tried to find it later at the computer.

If my estimate above is correct, I observed Meton, and there was a prominent crater, perhaps Archytas.

Now to the really cool event of the evening. I had to wait till after 2am untill Jupiter was clear of my tree's to the south, but there was the mighty Jupiter. I'm always disappointed in the lack of cloud detail I can perceive (powers ranged from 325x to 163x, keeping most observing with the 163x 12.5mm). I noticed the two prominant clound bands, with the southern main belt having a hind of a mid-level separation. There was a hint of a band on the northern latitude as well. I really need to hook up with some folks and compare their views to mine, I just have never seen any decernable detail on the bands, and I read all kinds of blogs about festoons, ovals, etc.

Anyway the main event of this evening was the transit of Io across Jupiter. As I watched in my eyepiece, trying to tease any surface details out from this challenging planet, I began to notice a bright object beginning to become more pronounced on Jupiter's limb, about the 11 o'clock position of the Io shadow. I immediately recognized this as Io itself. I watch for the next 45 mins or so as the moon grew more distinct as it approached the darker limb, until it separated completely from Jupiter's disk itself.

So I logged some new craters on the Moon, and saw Io transit out from in front of Jupiter for the first time. I would be interested in hearing back from others with SCT's regarding what you can decern on Jupiters belts. Please post any comments!

The lure of a Dual-Head Alt-Az mount

Ever since Orion Telescopes release a Dual-Head Alt-Az Mount about 2 months ago, I've been salivating. The price point is nice, at $399. The capacity of the thing is impressive, it can hold 2 telescopes each 25lbs. Now, that may very well be marketing, perhaps the mount can hold that much but it would be stressing the capability so much that shakes and tracking would be a challenge. So we will tone it down to say holding a 8"SCT and a 80mm Refractor, that is well within its capability.

Why a dual-head alt-az mount? Why am I so intrigued with the thought of having to manually track objects at high power when I have an equatorial fork arm mount that can track objects reasonably well w/o much alignment? I must say I have never used an Alt-Az mount, but have viewed through many dobsonians. The views are great, but objects like planets do not stay in the field of view very long at med-high power. You constantly have to adjust the position of the scope, thus you introduce some shakes, which of course then affect the view. By the time it settles, your object may very well be approaching the outer third of your field and on its way out. Now it may be argued that the Alt-Az mount is meant for low-med views yes, but I see all those Televue refractors out there on Alt-Az Gibraltar mounts and those folks are certainly not limiting those wonderful scopes to just low-med power views all night are they?

So there must be something to the Alt-Az mount, and certainly having 2 scopes is better than one. These are the things that make me go hmmm, I want one.

1. Family viewing. My 7yr can view through the 80mm, while I view through the 8" so I can describe whats in the field of view to him. I think the 80, with its much wider field of view, would be better for him. Of course this is for a certain class of objects, 80mm f/5 doesn't do much at all on planets.

2. Outreach. What better way to show folks the night sky then to have a dual mounted telescope. Again, you could be viewing through one telescope, while the newbie views through the other. Having the ability to see the same object that they are, without having to battle over the eyepiece would be wonderful. Newbies always have a hard time viewing through a telescope for the first time, so with this setup you could be describing to them exactly what they are looking at without having take their eye away from the eyepiece and of course you would be tracking the whole mount yourself so you guaranteed to have the object in the field of view at the same time.

3. Outreach again. You could have a wide field view going one side of mount and an 8" SCT with med-high power on the other. You would thus have two unique but complimentary views. Many people are fascinated the first time they view the Moon through a telescope. With an 80mm, they would see the whole disk. You could describe the lunar features such as Mare from the view of the 80, then have them take a look at craters or riffs from the 8" view.

4. Options. This point here worries my checking account and my significant other. Having a dual-head alt-az mount opens the door to more optics! I can now buy optical tubes w/o worrying about mounting much at all. Obviously you would need the appropriate rings and dovetail, but thats it.

5. Ease of Use. Perhaps the biggest draw to an alt-az mount is simplicity. All you do is take it out, mount the optics and start viewing. No need for alignment etc. Having a dual-head for a alt-az is simply a bonus.

I long to hear from folks that have purchased this mount and how well it tracks. In particular those with higher f ratio scopes that push up the power for planetary viewing. Until I can get a clear picture of this mounts performance in all area's of observing (low-med-high) its going to remain top on my wish list but not