Since
the times immemorial, the Moon has been a magical object of worship,
curiosity, and sheer fascination among people. Our only satellite,
it was considered one of powerful eternal Gods, immune to change,
ever-present, and influencing everything that was taking place
on earth. Women especially thought that the Moon had a tight connection
with the feminine, affecting their monthly cycles as it was affecting
the waters and all energy tides in the known Universe. Indeed,
with all we know nowadays about the Moon, with all terrific scientific
discoveries and even the manned voyages to the lunar surface,
we are still fascinated by it and the Moon still has a magical
spell upon many of us.
When,
in the spring of 1610, Galileo Galilei announced that he had discovered
something new about the sky, he became the first man to see the
Moon as a world made of the same material as our Earth, with all
its "seas', craters, and mountains. That famous breakthrough
forever changed the human vision not only of the Moon, but also
of the entire Universe. That was the beginning of a new, scientific,
as opposed to magical, approach to the astronomy. Literally, Galileo's
discovery made the heavens fall down on earth...
There
were numerous consequences of that new view of the Moon. In the
larger scale, it caused the fast decline of the doctrine that
the celestial ("heavenly") and terrestrial ("earthy")
worlds were opposite and separate realms. In addition, it also
raised a whole lot of new enigmas and questions about the Moon
itself. If it's a planet, just like ours, what is it like? If
the Moon is like the Earth, who lives out there? What is the weather
like on its surface? Is there any air to breathe? What are those
craters and strangely looking lunar objects, and why are they
so different from anything we have here on earth?
Many of those questions have been answered as our technologies
and scientific thought developed and was able to peek deeper inside
the lunar enigmas. Many, but definitely not all. With creating
this website, dedicated entirely to the lunar issues, we would
like to give our readers the picture as complete as we can about
various aspects of the Moon. We will attempt to describe what
is known and to highlight what is yet waiting to be discovered.
We wish to show different facets of the Moon as they are evident
to humankind in almost four centuries since the fascinating discoveries
of Galileo. We will lead you through the lunar knowledge in both
folklore and astronomy, the magical and the scientific, through
telescopes, photography, and space travel that allowed humankind
to finally step on the surface of our satellite. Keep tuned, as
there is a lot to know, a lot to think of, and a lot to still
discover about our closest and the most enchanting object in the
sky - the Moon.
Frequently
Asked Lunar Questions:
-
What are the basic measurements (diameter, density, etc.) of the
Moon and how do they differ from the same measurements of the
Earth?
The
Moon has a diameter of 3476 km and a radius of 1738 km. Its density
is 3.34 g/cm3 and the mass is 7.15 x 1022 kg. If to compare the
lunar measurements with those of the Earth, the Moon is much smaller
(the diameter of the Earth is 12,756 kilometres), less dense (the
density of the Earth is about 5.519 g/cm3), and its mass is about
one-eightieth of the mass of the Earth. Roughly speaking, the
Moon is four times smaller than the Earth and its gravity is six
times lesser.
- What are other lunar physical properties, including
its orbit and rotation?
The
orbit of the Moon is circular, and it spins around the Earth in
the same manner as the planets spin around the Sun, i. e. in the
counter-clockwise direction. The Moon revolves around the Earth
at roughly 2,300 miles, or 3,700 kilometres, per hour. Also, as
any other big space object, the Moon rotates on its axis. The
full circle of its rotation completes about once every 27.32 days
- in other words, one lunar day lasts almost one earthy month!
The distance from the Earth to the Moon is measured at about 384,400
km and the Moon is also slowly receding from the Earth (an annual
rate of the receding is about 3.74 cm.).
- Is there any atmosphere on the surface of the Moon?
The
Moon does have some atmosphere, although it is definitely not
suitable for human lungs. To be exact, the lunar atmosphere has
a mass of 10,000 kg, which is about 14 times less than that of
the Earth. The lunar "air" is composed mostly of hydrogen
and helium, which come from the Solar Wind, with an addition of
neon and argon, which are derived mostly from radioactive decay.
Such peculiarities and scarcity of the lunar atmosphere are responsible
for some intriguing differences between the Moon and the Earth
in relation to the sound and the light. In order to spread, both
the sound and the light need a more dense atmosphere than that
of the Moon. Therefore, the sounds produced on the Moon surface
cannot be heard, and the lunar sky always remains black. In addition,
winds and weather cannot be formed on the Moon due to the virtual
absence of atmosphere on the lunar surface.
- What is the lunar composition and how does its surface
look?
The
Moon is mostly composed of a handful of elements with a fair amount
of aluminium and silicate. A striking difference between the composition
of the Moon and the Earth is that the Moon lacks iron and contains
just about 100 minerals, while the Earth includes several thousands
of different elements and iron in abundance. Those differences
still make scientists scratch their heads. The lunar surface is
covered by very dry dust and rocks of various forms, alternated
by the famous craters, mountains, highlands, dark dry "lavia"
(seas), valleys, and lava plains. Indigenous water is absent on
the Moon. The only water that can be found there is brought by
meteoroids and comets.
- Do scientists know how the Moon was formed?
The
origin of the Moon is still unknown, although there are a number
of scientific hypothesis trying to describe where the Moon came
from. Actually, the issue of lunar origin has been a subject of
scientific speculations since the times of Galileo.
Before
the historical voyage of Apollo in 1969, three theories had been
formulated to describe the lunar origin. In 1878, the so-called
"fission theory" by G. H. Darwin (a son of the famous
Charles Darwin) linked the origin of the Moon to the early period
of the rapidly rotating Earth, which "spat out" its
large fraction that later became the Moon. Another hypothesis,
called a "capture theory", was formulated in 1909 by
Thomas Jefferson Jackson See. He suggested that the Moon had been
formed independently from the Earth, somewhere in the space, and
later was captured by the Earth orbit. One more scientific idea
stated that the Earth originally had been formed as a double planet,
and that the Moon had separated from the Earth during a later
formation period.
Already
after the Apollo voyage, in 1975, the journal "Lcarus"
published the modern "debris", or the "Big Whack",
theory of the lunar formation, which was formulated by scientists
Dr. W. K. Hartmann and Dr. D. R. Davis. In accordance with that
hypothesis, the Moon was formed during the late Earth formation
period, when our planet was hit by a smaller planetary object.
That powerful hit blew out a huge fraction of the Earth debris,
which took the orbit around the Earth and became our satellite.
The "Big Whack" theory of the lunar origin is still
supported and further developed by most scientists.
-
How old is the Moon?
The
age of the Moon is about the same as the age of the Earth - 4.6
billion years (this fact was stated by the scientists as they
measured the age of lunar rocks).
-
How many people have ever stepped on the lunar surface?
There
were total of 6 manned lunar
missions, which spread within the period of only 3 years,
from 1969 to 1972. During that stage of the lunar exploration,
12 men stepped on the surface of our satellite, and all of them
were Americans. Surprisingly, the Soviets have never sent a successful
piloted mission on the Moon's surface, although they were the
first to photograph the dark side of the Moon in 1959 via their
automatic spacecraft "Luna 3". It is also an intriguing
fact that, today, the Russians are the first to seriously think
about "terraforming" the Moon and establishing on its
surface the first ever human base outside of the Earth. Read more
about that in our future articles.
-
How does the Moon influence the rise and the fall of the oceans
on the Earth’s surface?
The
answer here is in the Moon's gravitation, the force of its orbit,
which powerfully pulls on the Earth and, thus, affects the big
basins of water. Within one day, the Earth oceans experience two
high and two low tides, both of which are influenced by the lunar
gravitation.
- What can modern science say about the "lunar
knowledge" imbedded in numerous myths and folklore of different
peoples?
In
traditional astrology, various myths, witchcraft, and shamanic
practices all over the world, the Moon has always occupied a solid
magical place as an object with a very powerful influence upon
people and events. The modern science has only started discovering
and explaining some of the “magical" lunar effects
that were known in traditional societies long ago - for example,
the lunar role of a cosmic trigger for natural earthly rhythms
and even breeding cycles. The effect the Moon' waxing and waning
has on the oceans, also touches upon every living creature on
earth, including people, as we mainly consist of water. In this
connection, some researchers claim that human suicide rates, as
well as the amount of accidents, violence, and psychic episodes,
tend to increase when the Moon is full. Cases of "moon madness"
and lunatism are still mainly unexplained by the modern medical
science.
©
2007 Lunacorp.com
|
