Star date: 04:12:99
The
Fun of Binocular Astronomy
We have all seen the beauty of the night
sky using only our unaided eyes. This way, we can see perhaps 5,000 stars
on a very clear night, from a very clear area. But what if we could somehow
increase the number of stars which we can see by thousands of stars? What
if we could see objects like Neptune and Uranus which are invisible to
the naked eye?
Certainly we can use a telescope, but
a good quality telescope costs
at least $150, and more often $200 or more.
In addition, many telescopes (those using
what are known as equatorial mounts) require at least some set up when
you begin observing each night. The advantage of equatorial mounts is that
once they are set up, it is much easier to locate objects. The other two
types of mounts for telescopes are altitude/azimuth or alt/az (usually
for smaller telescopes) and dobsonian mountings (usually for larger diameter
telescopes). The advantage of these is that neither of these require any
set up at the beginning of a nights observing session, but it makes it
harder to find objects which you wish to view.
Is there a way of being able to see more
wonders of the night sky and still be able to avoid the inconveniences
of a telescope? It turns out there is a simple answer, and that is binoculars.
Many people believe that the main purpose
of any optical device such as a telescope or a pair of binoculars is to magnify
the image, but this is not the truth. The main job of any optical device,
at least for astronomy, is to gather light. Just like you can move more
water through a larger pipe, you can receive more light through a larger
telescope, or pair of binoculars with a larger diameter objective (main)
lens.
What this means is that (with most objects,
including every galaxy and nebula) , you want the image you are viewing
to be as bright as possible, since these objects are dim.
Your image will also be more detailed,
as each little photon of light coming into your observing device contains
a packet of information about the object you are observing.
The sky is full of wonders
for the amateur astronomer using a pair of binoculars, and do not pass
up the obvious! The Moon is full of wonders for the binocular users. The
maria, which are the dark patches on the Moons surface come out in stunning
detail with a good pair of binoculars. These maria (Latin for seas) were
long thought to be actual seas of water on the Moon. We know them today
to be great plains of basalt, similar to common bedrock here on Earth.
The only possible water we know of today on the Moon is the recent discovery
of what appear to be large deposits of frozen water ice at each of the
poles of the Moon. It is likely that this water was deposited there by
comets (which are essentially dirty snowballs) which landed in craters
at the Moons poles. It was kept frozen there by the eternal shadows inside
those polar craters. The mountain ranges of the Moon are also a delight
to behold.
The constellation Orion
offers us an easy-to-find, beautiful nebula in its sword. This is M42,
a red and blue nebula. The red colors represent what is known as an emission
nebula, where ionized hydrogen (which was excited by energy from nearby
young, hot stars) falls back to its unexcited, normal, run of the mill
ground state. The blue color is what is known as a reflection nebula. This
is caused when the light from these young stars within the nebula is reflected
off of dust.
The planets in our solar system also
offer another interesting aspect of binocular astronomy. Look for Venus
nearly due west about 35 degrees above the horizon around 7:30pm all this
week. Although you will not see any detail on the surface of Venus (no
optical telescope in the world can), you should be able to make out the
fact that Venus displays phases, much like our Moon.
The most powerful explosions ever witnessed
by the human race were observed late last year, although they occurred
nine billion years ago. No one knows the cause of this explosion (or others
like it, although smaller) but although it occurred nine billion light
years away, it could, for a few seconds be seen from Earth with a pair
of binoculars.
Clear skies, and good viewing.
"Understanding is joyous" - Carl Sagan
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