Re: (SNES) Daylight Sighting of Saturn

["Les Coleman" <les11@cox.net>]

> You make it sound easy, but we all know that it takes technique and
> practice, as well as good sky  conditions to find the planets through all
> that blue glare in the daytime sky - at least until one has done it
> successfully a number of times.  I have been trying several years now,
> without luck, to spot a daytime Iridium flare at -7 or -8 magnitude.  To add
> insult to injury, my failures have been when I was equipped with the prior
> information where to look.  I've even tried with sunglasses to cut the glare
> of staring at that glaringly bright sky while trying to spot the flash.
>
> It would be very interesting if I might convince you to share your daytime
> planetary viewing techniques with us....?
>
> Respectfully,
>
> Les Lytton

Hi Les,

Actually, this is the first time I've ever bagged Saturn, and not for want of trying. The
problem with seeing planets in the daytime is not only the problem of a bright blue sky,
but the problem of focusing on infinity. Our eyes normally focus at a distance but not all
the way to infinity.  When they are focused in, the tiny spots of light are smeared out
over a large area and the loss of contrast makes them invisible. Another problem is
"saccades", a medical term meaning the minute twitching of the eye so that the fovea covers
an area larger than the 1 degree or so where it is in focus. You aren't even aware of
saccades most of the time, it is automatic like breathing but again like breathing can be
controlled with practice. If your eye doesn't "catch" something to see, it twitches to
another nearby point. So if you just miss Saturn, a few milleseconds later you are even
farther from it. Sigh.....

So how do we focus on infinity and learn to control saccades? Well here is where a nearby
object at optical infinity helps. The Moon is best because it is easiest. Pick a visible
high contrast point on the Moon. Practice holding it directly in view.
Switch to something else like a high flying airplane. If you stay in focus with the switch
you are well on your way to controlling both focus and saccades. Next try a thin crescent
Moon as it passes Venus.  Once you get that down, you'll have to practice the hardest
part - GETTING UP EARLY to watch a planet until the Sun is high in the sky.  I am a natural
early riser but my wife thinks I am crazy to get out of bed before I have to.

My process yesterday was as follows. I knew how far Jupiter and Saturn were from the Moon
(28.7 and 18.4 degrees respectively). I don't measure the angular distance but I do use my
hand as a rough gauge. I was actually going after Jupiter and not Saturn. When I looked,
Jupiter was very easy to spot. On Friday, Jupiter, the Moon and M44 (Beehive) will all be
together in Cancer, so I was just doing a "dry run". Jupiter was so easy I thought I'd give
Saturn a try. I had a very good idea where the Ecliptic ran because of Jupiter and the
Moon. There it was - Saturn. I double checked with my big binoculars. I got excited and
tried for Sirius. I couldn't see Sirius even though it was brighter than Saturn because it
was only about 15 degrees above the horizon.

I try to spot the planet I'm after by eye first. If I miss, I try with the binoculars. If I
find it there I can usually see it by eye afterwards.

Les Coleman
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