Stardate:05:03:98
Have You Ever Heard of the Eight Seas?
Our sister world has beckoned to the human race ever since the first
proto humans stared up from the Serenghetti plains. Tales of her charms
and beauty have been passed down throughout time. When a few of our ancestors
stared up at our lone natural satellite, they never saw the mountains which
exist on the Moon, nor the huge impact craters, or long rift valleys. But
they did believe they saw one kind of formation similar to the Earth. They
believed they saw seas.
The problem was, the seas didn't exist. Still, even today, we call these
areas seas. In a similar way, we also still speak in the so called "space
age" of the Sun or Moon "rising" or "setting".
In that case, perhaps, it is much easier then saying that at 6:31 pm local
time, the Sun will be fully occulted by the local horizon.
These "seas", known by names each beginning with the latin
word for sea - "Mare" -are Mare Tranquillitatis, Crisium,. Foecunditatis,
Nectaris, Nubium, Humorum, Imbrium, and Serenitatis. The size of the maria
added together make up about 17% of the half of the surface of the Moon
visible from Earth.
It is dark mares which we are seeing when we talk of a "Man on
the Moon". They are the dark, smooth regions of the lunar surface.
The details visible in any small backyard telescope in the maria make it
obvious that they clearly cannot be water, but that did not answer the
question as to their true nature.
For a long time, astronomers argued as to the nature of these areas.
Some thought they were large fields of dust blown by millions of years
of micro meteorite erosion on the Moon. Over the course of millions of
years, so went the school of thought, vast quanties of tiny asteroids would
strike the mountains of the Moon, slowly causing them to erode, spreading
dust for hundreds of kilometers across the lunar surface. We now know there
to be micro-meteorite eroson on the Moon. In fact, it is the only kind
of erosion we know of on the Moon. Still, it is not responsible for the
formation of the Maria of our sister world.
The other school of thought at the time believed that they were great
solidified lava flows. We now know them to be majestic stretches of solidfied
lava after all, covered in between a few centimeters to a few inches of
Moon dust.
The best time for any lunar observation is during time when it is "half
full". It is at this time that the balance between the length of the
shadows seen from crater's shadows is best balanced with the number of
details visible.
When the Moon is waxing (increasing in "size" each night),
the mares which may be seen include Mare Humorum, Nubium, and Imbrium.
Look for Mare Humorum and Nubium near the north (top) pole. Mare Humorum
is the one nearer the "rim" of the Moon. Next, look down to the
Moon's southern regions. Here you will find Mare Imbroum; the Sea of rains.
Mare Imbrium was the landing site of Apollo 15.
On a night when the Moon is waning (beacoming smaller each night), you
may see the Maria Mare Nectaris, Foecunditatis, Tranquillitatis, Crisium,
and Serentatis. The first three make up a triangle, with Mare Nectaris
at the top, about 1/3 of the way down from the Moon's northern pole. Mare
Crisium (literally, the Sea of Crisies) is just below, and out towards
the edge of the Moon, then Mare Tranquillitatis, the landing site of Apollo
11, is just below, and back towards the center of the Moon's face. Mare
Serentatis attaches to Mare Tranquillitatis, and Mare Crisium is alone,
out towards the outer visible area of the Moon, nearly at the lunar equator.
There are areas on the Moon where you can still today see where the
ancient rivers of lava rolled across the surface of our lone comapnion
world. Look for the river channel looking features near the edge of the
maria.