Gfamily

It does seem likely that many of us will struggle to see both ingress and egress, but if you're in the UK in a location where the weather deities aren't paying attention, the Moon will be more or less due South at about 9:20 with an altitude of ~40 degrees above the horizon - the Occultation starts some time between 9:30 and 9:40 depending on where you are. 

Thanks for those references.  I'd seen mention of Prof Ruggles, but didn't know that he had made so much available online.  

I've been asked if I can give a talk on behalf of our club to a group of customers from what you might call a "Crystals and Dreamcatchers" shop. They'll be at a luxury glamping site and amongst their other activities will be Forest Bathing and that sort of thing.

It's planned for the summer solstice weekend, so I've suggested a topic on The Solstices and how ancient people responded to it.

I'm happy to be able to put a scientific basis to what they're enjoying, and if I can help to put it in a historical human context I would enjoy doing that as well. 

It so happens that next year is also approaching a Lunar Major Standstill; which is when the Full Moon has its greatest Southerly ecliptic declination (actually in January 2025). This is related to the Draconic Cycle which marks the precession of the Nodes of the lunar orbit around the earth. As a result of it being the summer solstice and the lunar standstill, the Full Moon (early on the Saturday morning ) will be about as low above the horizon as it ever is at the Meridian. 

In terms of information about how neolithic people responded to the solstices, I'm fairly well able to find information that can be included, but I'm less sure about information about the Lunar effects. It's believed that many prehistoric constructions were built to align with the Lunar Standstill (for example the Callanish structure on the Isle of Lewis), and some of the 'recumbent' stone circles in NE Scotland, but I could do with pointers to relatively recent and (preferably) authoritative sources. 

Anyone able to help? 

Thanks

I'm not sure whether I posted this here a couple of years ago - but this is an image I put together to show the difference in the view from a dark sky site in Wales, and the view from our back garden in a town in NW England 

On 03/11/2023 at 20:57, Cornelius Varley said:

Your location makes more sense.

Could also have been in Santiago, Jo'burg, Adelaide or Auckland (to name but a few places) 🙂

40 minutes ago, maw lod qan said:

I've always questioned how you found some 4 to 5 feet in undisturbed soil?

Worms, moles and other burrowing animals mean that soil is constantly being turned over, and plant debris tends to stay on or near the surface. Meaning that non organic material tends to migrate to lower levels. 

13 hours ago, saac said:

These researchers put the amount of cosmic dust (micrometeorites) gained each year at around 5000 metric tonnes.  No doubt that will come with a fair margin of error. If that were distributed evenly across the surface of the planet what thickness (increase in waistline) would it represent?  This reminds me of the number of angels dancing on a pin head puzzle or maybe even a Fermi question; best contemplated with a few whiskies  

Jim

Given that Google suggests the area of the earth is about 510 million km^2, it's about 10g per km^2 per year.  

Less than a tablespoon of space dust over the area of an OS grid square. It would take a million years for this to equate to a tablespoon per square metre, and if you consider how thinly a tablespoon of sand would spread ...

Save the few whiskies for a different question. 

A recent xkcd  (if you're not familiar with xkcd, you can thank me later) 

https://xkcd.com/2849/

The campsite at Bellingham in Northumbria is being converted to being astro friendly with lighting being reduced where possible. They occasionally run star gazing weekends, though I understand they're very popular and book out quickly. There's a small Dob in the reception that can be borrowed. 

Our nights there were very wet, though we had one evening where were we chasing stars and planets through gaps in the clouds; never more than 2 or 3 minutes viewing for any single target though. 

But very dark skies (as you'd expect from a site near to Keilder).

13 minutes ago, Paul M said:

 

I've created a world class video of the event using HNSky on my coal fired Ubuntu lappy. Most of my astronomy is online these days so..Enjoy!!

PS. the middle 35 seconds is soooo boring...

Lol - I was going to say "Oh, and look out for the grazing occultation of that star (HD104864) " - but ...

1.  it's only 10th magnitude 
2. it's a blooming daytime occultation. 

Probably not then. 

22 minutes ago, SwiMatt said:

Sounds like a cool event to check out!

Just out of curiosity, does aperture make a difference in catching something like this in day light? I tried to point my Mak 127 to the Moon during the day, but it was very underwhelming. Would I be able to see Venus?

Yes, Venus should be easily visible - and I suspect that the surface brightness may be even brighter than the Moon's occulting edge*

*The moon's surface is fairly dark - with an albedo of about 12% it's similar to used asphalt in reflectivity - whereas Venus' clouds have a much higher albedo, reflecting up to 70% of the Sun's light.  

I know the pinned post from @Stu suggests that this forum is for 'less predictable' events, but looking at other threads, I see that's a guideline rather than a rule (apologies). 

Just to flag up that there's a daytime occultation of Venus by the Moon on the morning of Thursday 9th November. In my location it starts at about 9.40am and Venus will re-emerge about an hour later. 

Totally predictable and totally off topic, but might be of interest if people are free. Helpfully, Venus will be easy to find just beforehand as the Moon will be right next to it   

On 13/10/2023 at 17:45, Space Hopper said:

But i wonder if there may be other metals present as well ? Precious metals perhaps....? (My imagination running wild again - a gold asteroid in my head ! 😄)

Unless there has been a process to differentiate and concentrate the gold from the mix, having to extract the gold is where the problem would lie.

On Earth, economic extraction depends on finding veins created where subterranean hydrothermal flows have different metallic elements dropping out of the superheated water at specific pressure and temperature ranges. 

We know that there's billions of tonnes of gold in the oceans, but it's having a cost effective means of extraction (i.e. differentiation) that determines whether it's a valuable ore or not.

The issue as I see it, is that measuring density of individual asteroids is more than a bit tricky. It essentially comes down to measuring the perturbation of the asteroid as it is approached by other asteroids or planets (assuming you know the mass of the other).  

There are some asteroids for which we do have reliable masses, which are generally consistent - S type asteroids having lower density than M type asteroids. Of course, those to which we have sent missions have very precise masses - and Dawn visited both Ceres and Vesta (S type and M type respectively). 

On the basis that we have meteor remains that have densities that correspond to those of well established asteroids, we don't have a problem with most of them.

Nothing so far suggests that there is anything to support the idea of 'elements unknown to science' being part of asteroid 33 Polyhymnia.

As far as I can tell, there is no good knowledge of the mass of the asteroid.

The best estimate comes from a mathematical model of the solar system that interprets ephemeris data to determine how interactions between Asteroids allow calculations of masses

The asteroid itself is included in the paper for the 2010 version of the model (though that itself notes that the mass is 'unrealistic'). Later iterations of the paper do not include the asteroid in their tabulations.

Using a clearly unreasonable value for the mass as a basis for hypothesising the existence of ultradense matter (almost 4x the density of the most dense element) is umm, a stretch!

A paper containing the density calculation https://arxiv.org/pdf/1203.4336.pdf

Another paper giving the tabulated mass (not included in later versions)

https://arxiv.org/pdf/1011.4419.pdf

On 16/10/2023 at 19:56, saac said:

Those white phone boxes are seriously posh. Does anybody recognise this famous phone box - no googling unless desperate  

 

Jim 

 

 

 

 

I believe the film (not necessarily the best film ever, but one of many people's top 5) is available on the Channel 4 Catch Up service for the next few days. 

Spoiler for the Film Name under this link

ETA - Ooops, accidentally given away that it's associated with a film. 

Can you find some elsewhere?  They look similar to those used in better made cassette tapes.

2 hours ago, LunarRob said:

Great thanks for this info will check it out high Leigh isn’t far from me. Do people meet up and take their own telescopes? Thanks

Not sure about whether people take their own scopes

I understand that High Legh openng depends on the weather, but if you go to their website you can send them your phone number and they'll put you on a list to be messaged if they're running a Friday evening session. 

It's a bit further away for you, but I know that Liverpool AS always meet at Pex Hill (Widnes) observatory on Wednesday evenings, and people do take their own gear. 

On 17/10/2023 at 13:14, LunarRob said:

Hello all thanks for having me, i have started to study astronomy and want to get a telescope which will last me and give me the best possible view of planets, galaxies etc and maybe a little photography eventually but more viewing

 

Hi Rob

Depending on where you are in Cheshire, you may well find yourself local to one of several Astronomy Societies, which can be a good way of finding fellow astronomy enthusiasts. 
There are clubs in - Chester, Macclesfield, High Legh, Wincham & Pickmere and South Cheshire 

and my own club, the Mid Cheshire Astro Group who meet near Delamere Forest. 

If you look on the excellent GoStargazing.co.uk website you can see where and when they meet. 

https://gostargazing.co.uk/stargazing-events-future/

The RSPB are looking to know more about the practice, and have set up a website where you can let them know about where there have been heather burns.

https://upland-burning-rspb.hub.arcgis.com/pages/report-a-burn

It looks like the Brian Cox / Jeff Forshaw book is down to 99p on Google Play Books for today anyway. 

46 minutes ago, robin_astro said:

Ah ok I was just going on what was in the paper

Cheers

Robin

No problem - BTW,  well done on the 'place appropriate' name of your observatory - like like like ! 

1 hour ago, robin_astro said:

I don't think they are challenging the basic concept that planetary nebulae form from the outer layers ejected from red giants leaving a white dwarf, (A process which would still occur even in the absence of a binary companion) Just that the particular morphology and fine detailed structure (in this case and perhaps others) can be understood by considering  the presence of binary companions.  

The interview includes a comment that the number of PNs is significantly lower than would be expected given the population of suitably sized red giant stars.

If I heard it correctly, if almost all red giants of the right size were  to generate a PN, we'd expect to see far more of them. 

Also, (admittedly less convincingly) the observation is made that if the first two PNs studied by JWST show that a multiple star system is required to explain their structure (structure that was not previously obvious), then it may be more than a coincidence. But given the populations argument above, it may indeed be more than a coincidence. 

Hence, further analysis is required.

Details from the Liverpool AS website

https://liverpoolas.org/event/martin-mere-wwt-star-party/

Details from the WWT/Martin Mere website

https://www.wwt.org.uk/wetland-centres/martin-mere/whats-on/star-party-with-liverpool-astronomical-society

Booking required - tickets £10. 

When do Planetary Nebulae form? I've always read of them as being the last stage of smaller Red Giant stars; their outer layers being puffed off at their end of life. 

However, a listen to a recent Awesome Astronomy Podcast seems to suggest that 'it's a bit more complicated than that'. An interview with Dr Robert Wesson covered the results of the JWST imaging of the Southern Ring Nebula (one of the Initial Release images) and more recent imaging of M57 'our' Ring Nebula.

An article here about the JWST results that Dr Robert Wesson worked on, suggesting that PNs form within multiple star systems. 

https://scitechdaily.com/webb-space-telescope-reveals-mysterious-arcs-intricate-details-in-the-remains-of-a-dying-star/

and a copy of the recent paper on Arxiv.  https://arxiv.org/pdf/2308.09027.pdf

Further investigations are clearly required