|
Stefan
Mateescu made this text-scroller
Mini Observatory
Ursa Major - aka the
Big Dipper, is in the middle of the window.
Use the
scrollbars to change the view of the night sky.
Keep the vertical scrollbar above the middle to view the northern
hemisphere.
|
Chris Dolan made this
JAVA-applet
|
Computer Observatory
If you would like an
amazing observatory on your own computer - read on...
Stellarium is free
software which renders realistic skies in real time with openGL. It is
available for Linux/Unix, Windows and MacOSX. With Stellarium, you
really see what you can see with your eyes, binoculars or a small
telescope.
Download this great software for FREE here:
Stellarium
About the Moon
The Moon has
always held the power to mystify people.
The full moon has been linked to crime, suicide, mental illness,
disasters, accidents, birthrates, fertility, and werewolves, among
other things. Some people even buy and sell stocks according to phases
of the moon.
Here I will restrain myself to give you an explaination of the
phenomenon of the moon phases.
The earth's
one natural satellite, the moon, is more than one quarter the size of
earth itself (3456-Km diameter), making the earth-moon system virtually
a double-planet. Because of its smaller size, the moon's gravity is
one-sixth of the earth's gravity, as we saw demonstrated by the gigantic
leaps of the Apollo astronauts.
When the
moon appears smaller than a quarter, we call it a crescent.
When the moon appears larger than a quarter, we call it gibbous.
When the moon is getting bigger (phases New to Full) it is waxing.
When it is getting smaller (phases Full to New), it is waning.
For example, if today the moon were a waxing crescent, then tomorrow the
crescent shape would continue to grow larger, approaching first quarter.
After first quarter, the Moon would be a waxing gibbous, and continue
growing until it reached full. The moon would then begin to shrink,
becoming first a waning gibbous and eventually reaching third quarter.
Following third quarter, it becomes a waning crescent, and continues to
shrink until it becomes invisible at new moon. A helpful way to remember
whether the moon is waxing or waning is the following: A crescent moon
that looks like a "C" is shrinking (C for collapsing). If it
looks like a "D", then it is growing.
Another way to think of it is that the moon always grows or shrinks from
right to left.
The applet
below will show you all this in true time, meaning the image of the moon
to the left is how the moon currently looks, using your computers time
to operate, and the smaller images in the right panel shows the coming
events and their dates.
The following demonstration will
give you the reason why this is so.
The moon orbiting the earth once a
month, is lit up by the sun.
Thus, from viewpoint earth, sometimes we see the full moonface lit
up (full moon) - and sometimes the moon is between earth and the sun
(new moon) - meaning no moon visible.
Chris Dolan made this
JAVA-applet
|
