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Idle Reminiscence And Day 8-9 On The Moon’s Terminator

Idle Reminiscence And Day 8-9 On The Moon’s Terminator

Hi folks! You know, talking about the Moon and its affect on the weather (in Winter) in the land of my childhood, northern New South Wales, it seemed to me at the time, the clearer the nights got the bigger the Moon phases got and the thicker and colder

Hi folks!  You know, talking about the Moon and its affect on the weather (in Winter) in the land of my childhood, northern New South Wales, it seemed to me at the time, the clearer the nights got the bigger the Moon phases got and the thicker and colder the frost became.  In those days (please put me back) in the late 1940’s and 50’s when we young ones set traps for Bunnies (rabbits) for both meat to eat and skins to sell (three of us would set around 100-120 traps every day and run them 2-3 times a night).  The Bunnies came out to socialize a lot more on Full Moon nights than they did at other times.  I suppose daddy bunny could see mummy bunny

a whole lot better in the full moon light, eh!  It was also common practice to cut and bale ‘Fodder’ crops like Lucerne on the Full Moon.  We people on the land reckoned the crop grew a way better for the next cut at that time and I guess there were more light hours in the day then too.  So the Lucerne was cut and baled about every 28 days.

We were discussing (in an earlier article around Day 6-6½ the fact that we (the Human Race) were well on our way and really looking to our close planets with a view to paying them a further visit when everything stopped!!!  I guess the space programme then was fuelled by the Cold War between east and west and it would be remiss of me to suggest that it was a shame that ended.  But!  Having said that, maybe we do need to be a whole lot more outgoing in our approach to space travel.

We must realise that we will not get there without loss and there will be sacrifices made – that’s not to say we do this without regard for safety but you can practice for too long and the men (astronauts) who know how to do this are now ‘old men’.  The astronauts now are no less courageous or well trained but the old boys had the edge in having been there and we should have followed through.

When the British sent our forbears (convicts) out to what is now our Great Land ‘Australia’ they died by the hundred’s in shipwrecks and other incidents.  It doesn’t matter, I suppose now but a great number never reached the Great South Land.  Imagine, if you can, what would have happened if ‘Columbus’ had never made the attempt to cross the ‘Flat’ earth’s ocean (the Atlantic) to find the great land mass believed to be there or the ‘Mayflower’ had never sailed to deliver the pilgrims to the America’s or a hundred equally ‘impossible’ events undertaken with sheer courage because they seemed, at the time, to be needed to be done.

There’s around 6½ billion (and growing fast) of us at this time and we already think that is too many but, oh boy folks!  It’s going to get a heap worse and we (the human race) need to remove the proverbial finger and go forth and colonize.  With that in mind, one wonders why we are, in fact doing the Moon thing all over again!  We worked our way through all the ‘Apollo’ type missions with there return via the ocean (plash down landings).  Space travel evolved to the ‘reusable’ Space Shuttles’ (glide in landings) and now we do a back-flip and return to the old splash downs of yesteryear.  Progress eh!!!  I wonder have we not lost the way a little or does politics interfere way too much, as is usual.  Maybe they should just dish out money and encourage Private Enterprise to get us to the Moon and Mars with helpful input from the various space administrations.  Who really cares how much, just get it done so we as a race can move on.

Someone recently said that men on Mars (or the Moon for that matter) could do more in a few weeks than our little robotic missions can do in years.  The only draw back, if we let it become one, is money.  Hey!  Governments are wasting our money all the time, so it’s quite simple really, stop that and do this and I for one need to see this happen.  I don’t know about them but I’m on limited time here!  The Helix magazine of April-May 2009 issue 125 at www.csiro.au/thehelix, has a very realistic illustration of a Moon Base and not a bad little article, well worth a read.

Gee!  That was fun but now we better get on with our journey down the Terminator on Day 8-9.  We’ll start off as usual but a little south of the ‘Cusp’ with a quick look at a crater called ‘Simpelius’ at 70km.  If nothing else a little time spent in this area highlights the sheer ferocity of the bombardment received by the Moon in the early stages.  ‘Maginus’ at a really large 187km sits on the Terminator on day 8½ and looks more like a huge empty lake than an impact point.  It has been hit on its rim and floor several times by small impacts.  This carter sits just to the south of one that is as well known as any other feature on the Moon.  I speak of ‘Tycho’ visible every night from Day 9 forward until it sinks out of sight as the Moon goes through its ‘waning’ phases.  This crater measures in at 85km wide with a depth of 4.5km and was discovered by one ‘Tycho Brahe’ a Danish Astronomer.  It’s reputed to be around 108 million years old and has ejecta rays that extend out some 1500 kilometres in all directions except the quadrant between roughly SSW and due west which gives indication of the impacts entry direction.  These ejector rays were caused by the material that was expelled by the explosive force of the impact between Moon and Asteroid and indeed some of the close damage around ‘Tycho’ is said to have been caused by objects excavated from the crater by the impact falling back to the surface.  It’s been said that the bedrock below these craters can be shattered down to a depth of 10km and rebounds after impact.  The central Mountain Peaks to a hight of around 1.6km or so and the bottom gives new meaning to the word ‘rugged’.  ‘Tycho’ was visited by ‘Surveyor 7’ in 1968.

‘Tycho is an excellent example of inner-wall terracing (caused by subsidence over time) and is said to have been caused by a large ‘chunk’ of the same asteroid break up (Baptistina) that produced the piece that struck the Yucatan Peninsular in Mexico 65 million years ago.

Down to the north-east we go to a crater named ‘Walter’, this one is around 132 km wide and displays signs of terracing to the west of its rather obvious central mountain peak.  ‘Deslandres’ with a very nice little crater chain and ‘Hell’, a sharp little crater is in there too, best seen on Day 9.

‘Pitatus’ is a beauty at 88km sitting just to the west, south-west on the terminator.  It has small craters embedded in its western rim and is well worth some time.  Moving back to the north-east there’s a really nice 57km crater named ‘Thebit’ with its smaller impact perched on the western rim similar to that of ‘Pitatis’.  The three craters due south of ‘Thebit’ and tucked in behind ‘Deshandres’ are all in excess of 108km and make a good study piece with their central mountains and additional hits.  The southern most of these is ‘Walter’ followed to the north by ‘Regiomontanus’ and last but not least is ‘Purback’

Out toward the terminator from ‘Thebit’ on days 8½-9, lies one of my favourites in ‘Rupes Recta’ or to give it its common name ‘The Straight Wall’.  This fault or scarp is situated in the south-eastern sector of ‘Mare Nubium’.  There are three (3) features here that seem to be always mentioned together, so we’ll do that.  “Rupes Recta’ is a ‘Scarp’ of around 120km long and somewhere around 250 metres in hight with a perfect little crater just to the west of it.  The crater ‘Birt’ comes in at 17km and has an even smaller impact point sitting tight against its edge.  Just a little further to the west we have our third member of this threesome in a ‘Rille’ that runs parallel to the ‘Straight Wall’.  It is known as ‘Rima Birt’ and I would suggest that it is around 50km long.  The scarp really lights up with the sun on its western face and should be allocated some time on the above days (8½ - 9).

Our next target is made up once again of three (3) craters.  These are, ‘Arzachel’ at 98km, it has its own ‘Rille’ on the floor and a good central mountain peak with some slippage in the inner central crater walls.  A wee bit to the north, the second of the bunch is ‘Alphonus’, a fair crater of some 117km which seems to have a small ‘Range’ right across its floor and is also the sight of ‘Ranger 9’s’ impact.  This impact (or space probe) returned thousands of images from that area.  Number 3 of the trilogy is another big fellow at 150km wide and features a very smooth bottom or floor which only seems to have one (1) blemish – a very small crater on the east, northeast side.

Moving north once again we have a small valley named ‘Herschel’ at 41km to the west of it.  Our next stop is again further north in ‘Sinus Medii’ where we find ‘Triesnecker Rilles’.  These are approximately 215km in length and the crater ‘Triesnecker’ which is around 28km is right next to them.  These in turn lead us to the very popular ‘Hyginus Rilles’.  This Lava Tube network, (if one could call it that), resembles a clocks hands with a small crater for the hub.  A large telescope can show the caved in areas and a couple of places still seemingly intact, best seen on Day 8.

Over on the terminator on around Day 9 we have an area known as ‘Sinus Aestuum’ and its very well defined crater ‘Eratosthenes’.  At 58km this crater presents a very fine image with its terracing and exterior mountain setting (southern ‘Appennines Mts’).  Straight down the terminator from there we find another small crater named ‘Timocharis’ which is only 35km wide but is a fine, clean example that we’ll find duplicated a few times as we pass through ‘Mare Imbrium”.

‘Archimedes’, a lovely crater set at the northern end of a range of mountains of the same name is a spot where you can sit at the eye-piece for quite a spell.  The crater is about 80km wide and the mountains are 160km long by about 2km high.  To actually view these features first hand would be really something, eh!  There is yet another very small range a short distance to the north named the ‘Spitzbergen Mts’ and these measure around 60km long.

Now, to another favourite spot, the northern end of ‘Mare Imbrium’.  This is a location where I spend a fair bit of my Moon gazing time.  We’ll start with ‘Mt Pico’.  This monolith stands some 2.5km into space and is around 25km wide at the base.  The ‘Teneriffe Mts’ slightly west of ‘Mt Pico’ are a very popular spot that measures in at 180km long and 2.5km high.

A telescope trek to the east takes us to an area of mountains, rilles and the Alpine Valley.  The ‘Alps Mts’ are a very interesting 250km long and 2.5km high and incorporate the ‘Alpine Valley’ which stretches through the mountains for around 170 kilometres.  ‘Plato’ comes next and is in my humble opinion one of the finest craters on the Moon in its class.  Close up its beauty is breathtaking.  It has a width of 109km, thereabouts and to me resembles a huge mountain stadium.  The lava filled bottom of this crater is marked very clearly by very small craters and is only about 2km deep.  ‘Plato’ filled with lava that oozed up from its broken bottom, so the crater walls remain intact.

Given its rugged surrounds and its location on the edge of ‘Mare Imbrium’ and nearness to the southern edge of ‘Mare Frigoris’, this area can take sometime to inspect properly.  So, sit at your scope and play with different power and enjoy the feast.

‘Mare Frigoris’ continues through Day’s 8-9 but we’ve reached the end of our journey.  There is so much more to view on the moon than I can cover here, so arm yourself with some good books, maps and websites and go to it!

I need to thank my helpers for their wonderful reference material and my daughter (Sue) and friend Ed for putting it to print and posting to our website www.astronomy.abigbluesky.com.au

Reference material:

Moon Maps from www.astrovisuals.com.au

‘Exploring the Moon’ – by Steve Massey www.myastroshop.com.au

These are truly invaluable tools.

Thanks Fellas!