Hi all,
A second sketch in less than a week! An absolute flood compared to the previous 12
months!
I have sketched the crater Copernicus on other
occasions. I enjoy sketching this
magnificent ray crater as it has so much to offer no matter the phase of the
Moon. Since my last Copernican sketch,
I’ve come to find out more about this 95km diameter hole on the Moon.
The area around the crater Copernicus is fascinating, with so
much lunar history on display – from amongst the oldest to the newest lunar formations. From ‘ghost craters’ nearly totally lost in
lava flows from long ago, to relatively recent, terrifying massive impacts
whose devastating power is very much still visible.
Copernicus sits isolated surrounded by Seas and an
Ocean. These large areas of lava flows occurred
a very long time ago. The ghost crater
is Stadius is nearly as large as Copernicus.
But all we see today is barely the barely visible rim of its crater, the
result of an ancient impact with a very hot Moon that readily flooded the impact
hole with lava.
A newer impact is the crater Erastothenes. In structure it closely resembles Coperniucs
with clear features of large impacts such as central peaks, terraced internal
and external walls (the result of landslides of the steep walls). But it is an older impact than Copernicus
because the rays of ejecta material have been covered over by those of
Copernicus.
The rock that created Copernicus was a massive one. The impact through up an enormous amount
much material. Much was vaporized and pulverzied
that blew way out from the impact zone, being deposited as the rays that we see
today. There are even ‘shadow zones’. These formed when the cloud of polverised
rock raced over a mountain range and
eddie currents were created depositing material behind the ledge.
Another great feature of Copernicus is another set of
ejecta. Rock was not only pulverised but
also ejected out from the impact as huge bolders. These rocks inturn created their own set of craterlets. These craterlets surround Copernicus, even
forming strings of impacts. But these
are not considered Chain Craters as they are the result of secondary impacts
from a larger impact. Chain Craters are
a string of primary impacts. In the
sketch you will see one of the more prominent strings of secondary impacts. These secondary impacts are not trivial ones
either. Some of these craterlets are
over 5km in diameter which would have taken a substantially big rock to have
been thrown out to make such a large crater.
Conditions on the night were not perfect. If conditions were better a whole lot more of
these secondary impacts would have been visible.
This night I also took a photo of myself at the eyepiece
with all the gear I use while sketching.
The white box is a polystyrene box I use as a dew hutch to protect my
materials from dew during the evening. I
also made a video of the sketch. I’ll be
looking at making a time lapse video of this as a 3hour video of the sketch is
not gripping viewing…
Object: Copernicus
and surrounds
Telescope: C8, 8” SCT
Gear: 8mm LVW, 250X
Date: 7th
July 2014
Location: Sydney,
Australia
Media: White and grey
soft pastel, charcoal and white ink on A5 size black paper
Duration: approx. 3hrs
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