Bringing Astronomy to Cornwall


 Located at Court Farm Holiday Camp Site, St Stephen, Mid Cornwall PL26 7LE.               This is a dark sky site with a measured NELM of 6.0

 We are back after a long break, mostly in Africa, the site will be updated several times until we have caught up 23.06.15/1.08.15

 To contact the Observatory Either 07804 036959 (site), 01726 813602 (Office) or email

To keep up to date;- follow/like our Facebook page Roseland Observatory

 Please FOLLOW for updates. For additional information data visit the Contact Page see top tabs.

Then check all the other pages by clicking on the links at the top or bottom of the page.

 To stay with us just click on and follow the links, the camp site is close to Poldark country.

SS Computer Services when you simply need the best - just telephone 01726 68684.


Radio St Austell Bay; listen on 105.6 FM and on line for all the local news and events. Including a monthly contribution

from Roseland Observatory. This month on 28th April at 09.15AM

St Austell Voice;- Your local weekly newspaper carries a regular feature about the Night Sky on the first Wednesday of each month. Next time 6th May

Visit the Observatory;-  We have been on the radar for the organisers of youth and adult groups for a while now.

    £6.00 per adult, £4.00 for U 16's and U 8 foc, phone or email for more information.   To arrive safely please check the map on our Contacts Tab!

For Group bookings for schools, Scout & Guide Association members go to the News Tab on the top of the page. Please ring (01726) 813602 to book your place.  Check out the map on the Contacts page for directions.

 Learn More;-

LIFE & DEATH OF STARS the ever popular 10 week course is lead by Clint on a Tuesday evening starting at 7.00pm and finishing at 9.00pm at the Observatory. Just a bit below A Level. £5.00 per session. Is now underway.




May Night Sky;-



Taken from my contribution to the St Austell Voice.

LOOK UP;- Our new regular feature high lighting  attractive groupings of Moon, planets and stars.

Armillary Sphere;-  




Part of the Paralympics is in Cornwall - it is an Armillary Sphere

Image credit Sonia Clyne.

The distance to the Moon - results well nearly.  We have been working with a group of European and African astronomers to determine the lunar distance. I have got a copy of the draft paper and we get a mention.




Where did our water come from?

The astronomers say from outer space but is that the whole story?

The Oceans hold 1374 million billion tonnes of water with an average depth of 3.5 km. The diameter of the Earth is 12,750 km. The geologists say that during the formation period the hot rocks that resulted released vast quantities of water as steam and carbon dioxide. This atmosphere hung around in the upper atmosphere throughout the heavy bombardment period.

For it to leave the planet altogether it would have to have exceeded the planetís escape velocity or broken down to hydrogen and oxygen, the hydrogen would have moved into interplanetary space leaving behind an oxygen rich atmosphere for which there is no evidence.

The next stage according to the geologists is that it rained and rained for perhaps a million years forming the early oceans. The best estimate puts the oceans at 50% "Earth Water" and 50% from large "comet" impacts.

Why is this important at this time? Water is not 100% H2O some of it is D2O and the ratio varies from source to source. The D stands for Deuterium with a nucleus of one proton and one neutron, naturally this weighs more than H and so the water containing it is known as "heavy water"

The vast majority of sea water is H20, however some is HDO and a tiny proportion is D2O. In addition to the two isotopes of hydrogen (Tritium is discounted in this analysis) there are three isotopes of oxygen vis. O 16, O 17, O 18. This means that all natural water contains nine kinds of water molecules. The ratios of the different isotopes, one to another, can be measured using an isotope ratio mass spectrometer.

Naturally there is a gold standard type of water called VSMOW which stands for Vienna Standard Mean Ocean Water. It has superseded SMOW !


Water on the Moon. No less than 6 sources have been suggested for lunar water, the Sun, the Earth, the Moon interior, comets, asteroids, interplanetary dust and giant interstellar molecular clouds. The Deuterium/Hydrogen ratio has been measured many times and a wide scatter has been reported. This supports the overall view that to compare the D/H ratio of any extra terrestrial sample with SMOW to identify with certainty the origin of our water is speculative.

Universe Today 2014/12/11 carried a feature by Tim Reyes concerning water found within Comet 67P. Of particular interest is the infographic highlighting the D/H ratio of various solar system components including Earth and 67P. Earth is the base point if you like and the other bodies grouped around it. Now if we regard the sources of Earthís water to be many and various any comparison between it and other sources of water is an only an interesting exercise/ over simplistic?


Pilson MEQ Chemistry of Sea Water, Cambridge UP 2013

Stewart I & Lynch J Earth and the Power of the Planet BBC Books 2008

Rollinson H Early Earth Systems Blackwell Publishing 2007



Image Credit Tim Reyes Universe Today 2014/12/11

Where your work experience can take you. Alex was one of my early WE students and he then went on to a Masters in astronomy - he is now on the last stages. For his practical he launched a real rocket! To find out more just click on the link


Part of the tracking set up - a bit chill in Svalbard




I have recently made contact with a friend from long ago - he works now far away - Dean Ashton takes excellent images like this one 





   ASTRONOMY FOR INTEREST our ever popular 10 week course is lead by Brian on a Tuesday evening starting at 7.00pm and finishing at 9.00pm at the Observatory. Our entry level course, covers Sun, Moon, Earth, the solar system & stars. Observing the night sky when clear. £5.00 per session*. *Half the course fee goes towards membership of the group! This  course is now closed for the season to be replaced by fairly regular planning and outreach events.


Dawn nears Ceres;-





Learning More;-  Work experience for years 10 & 12;- Interested students should contact their school coordinator as soon as possible. See also the News Page. All letters and correspondence must go to the Par Office, 92 Par Green, PL24 2AG. and not the Observatory site.   Work Experience years 10 & 12;- Our very successful WE programme enables students to take a genuine part in the work of the observatory as trainee astronomers.











 All about Rosetta.


Comet 67P/Churyumov-Gerasimenko is the target of all this attention.  The P is a bit of a give away as it stands for Periodic as it has an orbital period of 6.45 years. Its discoverers whose names it bears found it on a photographic plate in 1969.  It is very unusual in that it appears to be two comets stuck together although I favour the theory that suggests that the necking evident on the images is the result of out gassing and loss of water ice.

 Image Credit ESA






One of the instruments is called Ptolemy  PI is Monica Grady - well known for her expertise with meteorites - an evolved gas analyser it will collect and analyse samples of organic material on the surface and use this to investigate how similar it is to materials found on other solar system bodies.

 Philae -


 I am Back;- from British Columbia - have been canoeing 200 miles up the coast - wild camping with whales and wolves for company. Just about to start a research project reconstructing Haida Astronomy. Oh and an earlier phase of the exped they found what might be a meteorite! - It is on a very very remote beach!



The next stage is to try and recover a sample cut and polish it to see if it contains metal or holes



UK's very own Space Weather forecast;- From the Met Office Exeter  comes the UK's first Spaceweather forecasts, they started in May and will ramp up in the coming months.

Naturally RAL Space the source of many of the instruments on the various Solar Observatories is heavily involved.  However we will have to wait before Solar Orbiter launches in January 2017 to get our closest views of our Star.


Prominences and active areas on the surface of the Sun.

An archive image taken through our H Alpha scope.


Shetland Astronomical  Society;   I was in Shetland in the summer 2011 working with the SAS.  Check out   To see Mike's - austroastro's video made from Chris Brown's images of the Northern Lights click on the link. For other U tube videos by austroastro do a Google search.

Mike in the Shetlands; - my main man up there has got his  website  running well - check it out it even links back to this one! He has just added Curiosity to his range of card models you can down load for free. Please note this one is 101 MB - just like the Dalmations. He has just added a solar radio telescope so we can now hear the Sun breathing(!) This is still in its Beta stage.

For the work we did together at Stargazing LIVE 2013 Mike made a model rover as a prize that was won by Thomas. Saw the lad again last week and he has the Rover proudly displayed in his room!


 Mike's model of Curiosity - this one is in Shetland not Mars.

Bodiggy School paid us a visit a few days ago here is some of the evidence





Astronautics Badge;- The UK Space Agency have sponsored a new Scout Badge. We are investigating the best way of delivering this to Cornish Scouts.




Joe Warrener who spent a few nights at Court Farm took this excellent view across the site.




The Pelican Nebula an emission nebula in Cygnus.


Image Credit Paul Hughes


To see all of Paul's images at full resolution go to  a lot of detail has been lost on the web page. His favourites file can be run as a slide show covering a range of deep sky objects.  





If you go down to the woods tonight .....! Image credit Anne-Marie

Science Technology Engineering Maths Ambassador;-  or STEM for short. Mainly for those wishing to get involved teaching with the Observatory. This is a National approval scheme that allows us to teach/demonstrate in schools and youth groups. Any one can apply (including those outside our team) is is good for those asked to go into schools to represent the companies they work for, Includes a DBS.  To learn more contact us via any of the Observatory links.

A great link from an American fan;-  Matthew H. found A kids Space Centre - Fun with Model Rockets - ( while working with his local library.


Mike working on the magnetometer        image credit Rob Stidston


Have your telescope in two places at once? Well with Slooh you can.

A good way to be able to image almost anywhere any time with your "own" Robotic Telescope. The Observatory has a "Commander" Membership.   


 The ISS;-  

The Space Station  is visible in our  skies  from time to time. See for exact times for you.   There are chances to see it in the daytime and towards dusk when it is getting dimsy.  

It Is so bright that it will flare as the Sun strikes one or two of the large solar arrays.     H-A are now giving suitable times for daylight passes. 

   Regular Opportunities for schools

 For more information about the courses see the "NEWS" page and then contact the Observatory.   

Key Stage One, Two and Three Astronomy. Opportunities throughout the Year  just phone and book, more  under News page on this site.

 Earth & Beyond; Doing Space this term then school teachers should see our News section. 

Gifted & Talented sessions for years 10 & 12 at the Observatory.

GCSE Astronomy Practical Project work. Having successfully guided many students through the GCSE Course work we  offer opportunities on a regular basis. Opportunities throughout the year  just phone and book. Only £5.00 per session. In each case email or phone (01726) 813602 to learn more.  

 Extended project A Level std. Global Dimming. This experiment was extended this year into the IR as it  produced a clearly measurable change in light levels through the previous Christmas period.

 For Scouts, Guides and other youth groups see the separate News Page.


 The Neptune Saga;- Continues with a new book about Le Verrier which fills a black hole in our knowledge of 19th cent. French Astronomy.  Written  a review for publication in a number of journals. Also the long awaited paper on the subject has now been published see below in the main Neptune section. Anyone wishing to read it please request a PDF copy.

Neptune's orbits - a paper  by Norma Foster is also in the Antiquarian Astronomer and compares the actual orbit that Adams calculated and puts right a  view,  long held,  by some that the position he predicted was a long way from that calculated by Le Verrier.  Those wishing to read it please request a PDF copy.

 Our Neptune research has reached the august pages of the Antiquarian Astronomer issue 7 March 2013.  it covers some 11 pages and is described as "incisive".



 Taken during the Society for the History of Astronomy autumn conference 2011.

Neptune's special year;- The year 2010 opened in January with a special presentation in Seattle, USA. NB The Blue Planet is close to opposition at the moment so a good time to observe given clear skies.

Image credit "a friend" 

Note the Cornish Flag!





Neptune from Voyager  2                         Credit;- Jocelyn Murgatroyd and Cornish Cross Laneast












Images by John Chiswell from two cameo reliefs. The lady is Eliza Adams nee Bruce  - It is believed to be the only likeness in existence. The sculpture was by Albert Bruce-Joy a relative and well known artist.



This image is of the memorial in Westminster Abbey and is also by Bruce Joy. Image Credit Westminster Abbey.


 Bill Sheehan's Neptune  with 10" RC.


Neptune discovery story. For a short film of the Neptune story visit Maarten Roos website. 

Have continued my researches by contacting the Chinese University in Hong Kong (been there got the T.Shirt). Some 10 years ago they did some excellent work on Neptune's orbit which I now have permission to use in my talks.

For Canoe Africa see below.

The Hurlers;- 

World Heritage Site;- We are currently working with Caradon Archaeology on The Hurlers.  (Minions is the  nearest village) This work is centred on how to best interpret these ancient sites to an interested general public. At the moment we are helping with an APP to interpret the area in a modern way. Thanks to Cornwall Council and Cornwall Heritage Trust for their support. The Apps are now on a an APP store.

The  background;-  The Hurlers can be found on Google Earth 500 30' 58.67"N   40 27' 29.69" W, the aerial view is  supplemented by a number of photographs and some text. Until recently people studying the various monuments around the country would look closely at one aspect or site and not regard those near by. The Hurlers are the focus of a much larger complex of ancient structures.

Winter Solstice;- It was Hurlers time again. A group of the intrepid marched out to Craddock Moor Circle, as we have said before more or less invisible on a featureless moor it surrounds a very large gorse bush which as been cut down and removed. Difficult in daylight but in the dark..... However in spite of the cloud the Sun was seen rising above the Bronze Age cemetery shades of Newgrange perhaps. Sunset is in line with Tregarrick Tor, this tor is not a skyline feature though, further investigation is in hand. An image has just been taken sunset 24th! a report to follow from Robin. Iain Rowe a local historian and expert on Bodmin Moor walked along the 130 bearing from Craddock Circle to a cairn on Caradon Hill by way of Minions Mound. This is a nice secure alignment. - Thanks Iain.

It was the Equinox again! We gathered lots of extra data and the weather ranged from great to fog so thick it was not possible to see across a Circle. There are two Equinoxes on the 23rd the astronomer's equinox and on the 24th the landscape version. On the 23rd 2014 the Sun is overhead at the equator as the Sun moves from North to South. On the 24th the Sun rises due East at 7.00AM BST  - 6.00AM GMT although longitude and the Equation of Time also need to be taken into account.  The difference between the two is due to refraction which causes the Sun to appear to be above the horizon earlier than it actually is.  The whole package is being written up as  the "Proceedings of the NAM Conference" we attended in the summer.

Mapping the Sun Day 12th July 2014 at Sterts Arts Centre, Upton Cross. This event went well with about 50 archaeologists attending.  Checked out the orientation of the Rillaton Barrow and found the entrance is open to the Equinox sunrise! However it is believed that the entrance is nothing more than a gap left when the cist was rebuilt after the miners dug out the gold cup!  Not with standing the rising Sun does light up the entrance on the Equinox.

Image credit Mike Clarke


Back to the Hurlers. Lead by Gary and supported by Amanda we measured the elevation of Rillaton Barrow above the horizon step by step using a professional level.  We had good results although more work needs to be done. We have proved which star it celebrates and when it was built. We seem to have identified the Processional Way referred to by John Barnatt in "Prehistoric Cornwall".

The Calendar Stone is to be found in the Centre Circle and to the south of centre. For all time people  have noted that shadows cast by trees or stones change their length and direction during the day and throughout the year. The length marked at midday once a month requires only 7 marks to define the solar year. A more complete explanation of this system is available.

Archaeologists are often rightly sceptical of two point alignments and require either a Back Sight or Fore Sight to support the evidence. Extend the Hurlers SW - NE line northwards about a kilometre to arrive at Tumuli. Due north is Stowe Hill due  south is Minions Mound with more Tumuli. (Tumuli are Bronze Age burial sites.) Due East is Kit Hill,  west is a large barrow. If you turn your back on Kit Hill and look towards the Pipers you will find they lie one behind the other i.e. due west. Stand between the Pipers and look towards Stowe Hill and you look North. Are the Pipers contemporary with the Hurlers - the evidence points in a positive direction. 

The N - S line can be extended on to Long Tom,  Menhirs or Long Stones predate Stone Circles and this one has had a Cross carved on it at a later date. Although not exactly due south of the Hurlers it is south of Stowe Hill which is a long ridge of high ground.

Vernal Equinox;- To celebrate this we  visited the Hurlers  on the Sunday 25th March 2012    Sunday AM was good in that it was clear and we saw the Sunrise, close to Kit Hill although Kit Hill itself was not visible to the naked eye due to general murk. Sunday PM saw the Sun setting due west close to a couple of burial mounds as predicted. 

Summer Solstice;- It so happens that the midsummer Sun rises above Stowe's Hill and sets over Brown Willy. Summer Solstice 21st June and we were at Craddock Moor Circle for the event.  A first for us was an observation of a special Standing Stone on Stowe Hill It seemed to mark the actual position of sunrise. (June 2010)

From Craddock Circle the Sun rose behind the Cheesewring on Stowe Hill as predicted, what was new to me was to see the Sun hitting Tregarrick Tor before it rose for us, this confirms that Tregarrick marks the winter solstice sun set. (June 20th 2012)



                                      The Sun rising over Stowe Hill    (2012)                                       

 Image by Amanda King of the Roseland Team.


Summer Solstice 2013;- The group ambled out Craddock Circle. It is a circle of fallen stones close to gorse bush atop a featureless hillock. The Sun had shown signs of remaining visible until sunset but it was not to be. However it appears to set just west of Brown Willy. Images had been taken a couple of days before and will be examined in the Observatory.








7th June                                                                                                             19th June

Many thanks indeed for the images from Robin Paris of Darite - excellent and revealing sunsets. A CD has just arrived with more images all adding to our overall knowledge of the Bronze Age calendar.

Autumnal Equinox;- The Sun rose and set as per the Vernal Equinox, although on the date we were there (21st Sept. 2011) the fog was so thick it was impossible to see across the Circles!

This time using a solar filter in conjunction with a small telescope it was possible to determine that the Sun rose just a bit to the right of Kit Hill stack. The sunset was impossible due to thick cloud. 22nd Sept 2012. Same situation Sept 2013.

Winter Solstice;- The three stone circles known as the Hurlers near Minions, Bodmin Moor. Appear to mirror the well known asterism of Orionís Belt in the centre of the Orion constellation.

21st Dec Mid Winter Solstice 2013;-  Usual pea souper of course up on the Hurlers - Bodmin Moor, so we were unable to do much until after breakfast. The modified compass worked well to gave us a real baseline for the first time. Checked out Kit Hill again as due East and established the position of the "4th circle". We were unable to do the Sun rise from Craddock Circle. Just too foggy at sunrise.

In the 21st cent. this constellation, including Orionís Belt, is due south of the Hurlers on the  winter solstice (Dec 21st) at midnight. In the Bronze Age circa 2000 BC this transit occurred earlier in the evening due to precession.  Remember the actual day of the winter solstice was marked from Craddock Circle. Due north was marked by Stowe's Pound and the ďever presentĒ pole star, in those days Thuban in Draco and later Kocab in Ursa Minor. Directly north of the Hurlers is Stowe Hill with its Neolithic enclosure and Rillaton Barrow, the Bronze Age users of the Hurlers would have recognized that the stars directly above the Hill did not move and were therefore special. Today the star that occupies that place is called the Pole Star, North Star or Polaris.

 There is no doubt that the view of the Hurlers would have been very special before the Quarry removed much of the viewing area. However even today the torch lit Circles look impressive indeed.


             Paul Hughes of the Observatory Imaging Team

The Three Circles lit by torches, giving a very atmospheric effect.  It seems that at this time the winter solstice was celebrated all over Europe by the lighting of bonfires. It consists of four individual images merged into one.  It was normal for special events to be marked by lighting fires. We carry this practice forward today with our Torch Light Processions and lights on Christmas Trees and in public places.

The role of Craddock Stone Circle;- One question often asked is, how did the people of 2000BC know which was the shortest day of the year? It just happens that one of very few winter solstice alignments on the Moor is between the nearby Craddock Stone Circle (1 kilometre distant) and Tregarrick Tor.  There is even a raised embankment avenue joining the Stone Circle to the Hurlers complex - problem solved.

Clearly the Hurlers were very important in the Bronze Age and this should be more widely recognized and appreciated.

 Update;- A summary of work carried out in the county appears in "The Hurlers an Archaeological Assessment" published by the Historic Environment Dept of Cornwall Council.

Mapping the Sun Project Sept 2013;-

The Equinox problem solved - Maybe?;- The Sun  does not rise due East (above Kit Hill) on the Equinox but does rise early, these two problems are linked.  Refraction is well known as the reason for the Sun to become visible while still below the horizon.

The Hurlers;- A combined project (Sept 2013) with the county archaeologists culminated in a nine day "Summer School" on the Hurlers. Called "Mapping the Sun" Involved survey work and mapping the Sun rise and set positions. We have created a Bronze Age Landscape map - working with a range of specialist kit new and old to achieve this. New Discoveries were made and new Legends were born. The archaeologists uncovered, examined, photographed and recorded a quartz pavement that last saw the light of day in 1938 and using modern techniques will learn so much more.



 Orion's Belt on Bodmin Moor. The image was taken, with great expertise, by Tony Piper located on  Caradon Hill. Single torches were placed in each of the circles. The result shows how closely the torches resemble the stars in Orion's Belt.


This lovely sunset picture showing two of the Hurlers lit torches was taken by Paul Hughes of the Observatory team




Martin, a German visitor to Cornwall filming the Hurlers from his Quadrocopter.

His You Tube videos can be found on Thesnaptin Image Credit Robin Paris


Canoe Africa;-  To find out more about my attempt to spread the astronomy word  click on my link Canoe Africa   and visit our special Canoe Africa page. See also check out the reports filed under IYA 2009. The dates are Sept 9th 2008 and Feb 12th 2009 - Thanks to Tammy Plotner.  







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