Meeting notes plus Society and Space News by David GlassWelcome to the November newsletter, published as Slides presented at our September meeting. As follows:
Space News by David Glass
Welcome to the April newsletter. In order to reduce the work in our monthly newsletters, we now publish the Slides presented at our April meeting. As follows:
See the Albeireo page on wikipedia.
Welcome to the December newsletter. Sadly, on many fronts, the Covid crisis continues, so I hope you all managing to keep well and keep occupied. The weather clearly hasn’t cooperated much this past month. Aurora have been seen and photographed, Comet Leonard is approaching visual visibility – I think I picked it up in binoculars on a strongly moonlit night a week or so ago – but I may have been kidding myself! Orion is now prominent, so some fun to be had there if the clouds disappear. Jupiter has been looking nice but is now getting rather low for good clarity.
On a practical society note, we have the AGM this coming Thursday, December 2nd @7pm, along with David’s astro-quiz. The night will only be on Zoom and not in hybrid format, so don’t turn up at the museum, there will be no one there. Should be a fun night – no pressure David. Festive hats are not a dress-code requirement, but here is nothing to stop you!
Ian Bradley, on behalf of the EAS committee.
Recent images – Ian BradleyAbove: November 24th. The great Red Spot is just visible and the Moons Io [left] and Europa [right}. Click toenlarge. November 13th. Seeing was much better. Click to enlarge.
Astronomy News – David Glass
At the moment there seems to be a pause in the construction around the launch area, with a lot of cranes etc taken off site. The massive tower holding the “chopsticks” intended to catch an incoming booster and position a starship on it are essentially complete, and much of the scaffolding around it has been taken away. On 12/11/21, all six Raptor engines on Starship 20 were test-fired. There is also a booster rocket (BN4) in the launch area which has Raptor engines fitted, but BN5 in the construction area is catching up fast and it’s not clear which one will be used for testing and a future launch. There’s a very nice discussion of what’s happening here.
At the moment it’s unlikely that there will be a launch to orbit in 2021, but we can look forward to more tests and possibly test flights of booster and starship separately.
Another outfit has joined the select group who have put a craft into orbit. This time it’s Astra, who used their relatively small rocket to put a test payload into 500 km high orbit. This was achieved after just 5 years’ development. Their aim was to develop a small 2-stage rocket and launch system that can be mass-produced and launched from spaceports anywhere on the planet. This “Rocket 3” development can carry a 50kg payload to orbit, and a planned “Rocket 4” should be able to carry up to 200kg.Astra LV0007 take-off for orbit. Credit: Astra. Click to enlarge.
The launch site for this was Kodiak Island in Alaska, which emphasises the wide range of launch sites that could be used for this rocket.
James Webb Space Telescope
The launch of JWST will be a huge event in astronomy and astrophysics, which so many science goals depending on its successful launch, deployment and commissioning. So, the last thing that people want to hear right now is that a failing clamp sent an unexpected vibration through the spacecraft – which is precisely what happened. Engineers seem to be quietly confident that everything is OK with the spacecraft, which is robust enough to withstand launch into space. However, nobody needs that additional stress! The planned launch date in December may slip a bit, but we will have to wait and see.
We all know that there are near-earth objects (NEOs) orbiting the Sun. At the moment none of these pose a significant risk to the Earth (although the name Apophis does pop up in news articles from time to time!), but one day we may detect one that could collide with the Earth. So, what can we do about it? The Double- Asteroid Redirection Test (DART) is designed to see whether the course of a smallish asteroid can be deflected by a spacecraft impacting it, and its spacecraft was launched this month to intercept a binary asteroid, 65803 Didymos. The larger of the bodies is about 780km across, but the smaller one is about 160km across. This a size of interest in terms of protecting the Earth, because there are a lot of them and not all of them have been detected yet. The aim is to create a small deflection by crashing the spacecraft into the smaller body. The deflection should be measurable by tracking the asteroid from Earth, and there’s already been an intense campaign of observation to determine its current track.
There’s a nice description of the mission here.
And, if you want to become a certified “Planetary Defender”, you can take quiz!Schmatic of DART spacecraft crashing into its 160km diameter target asteroid. Credit: NASA/Johns Hopkins Applied PhysicsLab). Click to enlarge.
Practising for the Search for Life on Mars (or Elsewhere in the Solar System)
Modern astrobiology depends on being able to recognise signs of life here on Earth, in order to spot it elsewhere in the Solar System (or possibly beyond – roll on JWST!). This means that astrobiologists can be found deep inside caves, in submarines at the deep ocean floor near hydrothermal vents, risking their existence near boiling volcanic lakes etc trying to gather samples of life in the most extreme environments known. A study published in October didn’t go this far, but concentrated on a hostile, arid environment that could represent conditions on Mars. They concentrated on finding compounds that are associated with cell membranes, proteins, and immune response. Key to this was the development of their “LDChip”, a single device for detecting key molecules which may find its way onto future spacecraft.
The rocks they investigated were carbonates from the Atacama Desert, Chile (where the ALMA telescope is located). The rocks are thought to be from between the Triassic and Jurassic eras, when a huge mass- extinction event occurred. The results showed limited signs of life, associated with cell shutdown and survival in harsh conditions which could be expected if a mass-extinction event was underway.
The full paper on this research is here.
But a summary with more detail than in this newsletter can be found here.Atacama Desert, Chile. Credit: Nikolaj, https://www.zastavki.com/eng/World/wallpaper-112744.htm. Click to enlarge.
New Ion Propulsion System Using Iodine, not Xenon
Several spacecraft have been powered by ion-propulsion systems, where an electric field is used to accelerate ions to create a thrust. The Hyabusa-2 spacecraft which successfully got samples back to Earth from the asteroid 162173 Ryugu used one. The thrust from these systems is tiny, about that of the downforce of a small hedgerow bird sitting on a branch. However, the thrust can be applied for months at a time and the effect on a spacecraft’s trajectory is dramatic.
Traditionally, these systems have used xenon gas (relatively heavy atoms) to provide the ions. However, a team has now developed an ion-propulsion system that uses iodine instead, which is abundant on Earth and produces more thrust than a xenon-based system so less propellant mass is needed for the same job. A downside though is that iodine is corrosive, so electronics and other potentially-affected systems on a spacecraft have to be protected adequately. The new system has been tested aboard a 20kg Cubesat launched from China in November 2020. A full description of the engine and its performance can be found in an article in Nature (getting published there is an achievement in itself!), available in full here.An iodine-ion propulsion system under test in a vacuum. Credit: ThrustMe. Click to enlarge.
Winter Coloured Double Stars – Ian Bradley
Double stars can be very pretty, especially if the two stars have contrasting colours. Double stars have the advantage that they are little affected by light pollution or the phase of the Moon, unlike for example the faint fuzzy blobs of galaxies.
Splitting very close doubles can be an interesting challenge but you may be limited by the resolution of your optics. A very rough rule of thumb is that on an ideal night [do we get those in Cumbria?] your binoculars/telescope can resolve objects that have an angular separation of 140/aperture in mm [5.5/aperture in inches], so for a pair of 10×50 binoculars, you could separate stars if they are 140/50 ~ 3 arc seconds. I suspect 5 arc seconds might be a more likely possibility in this case.
Generally double stars with a colour difference are more interesting and beautiful to observe, especially if they are not too different in brightness. Having said that Castor, α Geminorum, is a pretty double with both stars being white and having a similar brightness.
One classic and rather lovely double star is Albireo in β Cygni – the head of the swan.Click to enlarge.
The picture above is one I took in September using my 8” Meade SCT and a Canon DSLR. The primary star is a lovely golden yellow at magnitude 3.4 whilst the companion at magnitude 4.7 is a lovely blue colour. They are just splitable using a x20 magnification.
The annotated right-hand picture defines a few of the numbers in the table below. North is up as seen in binoculars, but be careful here as different styles of telescope with give different orientations (never mind the effect of a star diagonal!). For example, a Newtonian, Dobsonian or refractor will give west to the left and north down, whilst a Schmitt-Cassegrain or a Maksutov will give North up and East to the right [as will a refractor and a diagonal).
So what do the labels mean? The separation is just the angular separation in arc seconds of the two stars, whilst the position angle is the angle of the line joining the two stars measured going in a direction through east – so can vary from 0° to 350°.
In the table below;
- are the positional coordinates RA (Right Ascension) and DEC (declination), the equivalent of latitude and longitude;
- the magnitudes of the two stars;
- the colour difference where the bigger the number, the more distinct the difference, determined from the spectral class [colour] of the stars;
- Finally, the optimum magnification based on the opinion of Alan Adler. He found that doubles look their best at a magnification that is approximately 750 divided by the separation in arcseconds. So, for Alberio, where the separation is 35”, 750/35= 21, so 21x magnification looks best. This is a rather subjective measure and don’t worry if you can’t get this ‘optimum’. For example, with my Meade, my minimum magnification is 77x and Alberio looks great!
Sometimes, the human brain plays tricks on you. Despite the temperature of a star, which fixes the colour and the spectral class, if the brighter star has a strong colour, you perceive the fainter star to have the complementary colour [for red that is cyan] rather than its true colour! You’ve probably seen this with an afterimage after looking at a bright coloured object. This is a nice website on this point. And different people see slightly different colours just to confuse things even more.
The following is a list of winter coloured double star systems worth looking at for their colours, based on a 2016 article in Sky and Telescope by Bob King1 – who based his article on an earlier one by Alan Adler2. You might need some planetarium software to find some of these pairs.
|Star||R.A. Dec.||Mags||Sep.||P.A.||Colour difference||Spec. class||Optimium magnification|
|η Cas||00h49m||+57° 49′||3.5||7.2||13″||317°||1.7||GO, K7||58x|
|1 Ari||01h50m||+22° 16′||5.9||7.2||2,9″||164°||3.5||K1, A6||268x|
|γ And||02h04m||+42° 20′||2.1||4.8||9.8″||64°||3.5||K3, B8||77x|
|ι Tri = 6 Tri||02h12m||+30° 18′||5.3||6.7||4″||69°||1||G5, F5||188x|
|η Per||02h51m||+55° 54′||3.8||8.5||22″||301°||3||K3, A3||27x|
|32 Eri||03h54m||–02° 57′||4.8||5.9||7″||254°||2.6||G8, A2||107x|
|ρ Ori||05h13m||+02° 52′||4.6||8.5||7″||64°||1.7||K3, F7||107x|
|14 Aur||05h15m||+32° 41′||5.0||7.4||15″||226°||0.4||A9, F3||50x|
|ι Ori||05h35m||+05° 57′||2.9||7.0||10.9″||142°||0.2||O9, B1||69x|
|ι Cnc||08h47m||+28° 46′||4.0||6.6||30.6″||307°||2.6||G8, A2||25x|
|ζ Lyr||18h45m||+37° 36′||4.3||5.6||44″||150°||1.1||B7, A8||17x|
|Albireo||19h31m||+27° 57′||3.4||4.7||35″||54°||3.5||K3, B8||21x|
|31 Cyg||20h14m||+46° 44′||3.8||4.8||107″||325°||29||K2, B3||7x|
|β Cap||20h21m||–14° 47′||3.2||6.1||307″||267°||3.2||K0, B8||4x|
|γ Del||20h47m||+16° 07′||4.4||5.0||9″||67°||1.4||K1, F7||83x|
|δ Cep||22h29m||+58° 25′||4.1||6.3||40.9″||191°||2.5||G2, B7||18x|
Some recommended highlights:
- Eta (η) Cas: Exquisite at 64× with a pale-yellow primary and purple-red secondary.
- Alberio β Cas: Lovely yellow primary and blue secondary but some people see yellow and white!
- 1 Ari: A close pair. Orange and blue – a good example of complementary colour.
- 14 Aur: Yellow and pale orange; subtle.
- η Per: Reddish-orange and blue-green. Another example of complementary colour.
- 32 Eri: Yellow-orange and blue. A close pair, so use 100× or higher to see the colours more clearly. Could be a challenge to find.
- Iota (ι) Ori: Two pure white suns. No colour difference, so no false contrast here!
- Gamma (γ) Lep: Striking gold and green! Of course, since there are no green stars, the complementary perception effect is at play here. Sadly, this is quite low, below Orion, but worth a try
I’ve only seen a few of these but I hope to see some more. I hope you can see some too.
And… the November newsletter.
Well, winter is nearly here with the end of summer time. Nights are drawing in, cloud guaranteed especially when there is some time-limited viewing opportunity or aurora likely! Such is astronomical viewing in Cumbria. All you can do is get out when it is clear and enjoy. This month’s sky notes give the usual details of what is visible, subject to me discovering them as I’m not very good at looking for unusual events like planets or comets aligning up with each other or interesting deep sky objects.
In addition, this month, there are some details of a comet, Comet Leonard C/2021 A1 which has the potential to become quite bright [here we go again?]. This particular long period comet has been around the Sun a few times, which tends to make them more predictable as most volatile materials will have vapourised in previous perihelia. Volatile materials in ‘new’ comets tend to cause sudden outbursts leading people to think it’ll be much brighter when it gets closer to the Sun and so they often disappointed when the volatiles then stop vaporising and the comet dims. Hopefully this comet will behave and not disappoint when it is closest to Earth on December 12th. It is quite well-placed in the early morning sky in early December but rattles low along the western horizon in the evenings. Fingers crossed.
Committee members required. David and I have worked hard to keep the the Society alive and active. We really need to keep the momentum and help the Society to grow. For this, we really need some more people on the committee. David and I are getting somewhat ‘burnt out’ so we do need help. Please think seriously about volunteering, and let us know at a meeting or by email if you can help.
Also, don’t forget, contributions to the newsletter from any member are most welcome. They could be stories, historical snippets or photographs.
Ian Bradley, on behalf of the EAS committee.
Thursday November 4th, 7pm Kendal Museum, or online on Zoom.
Speaker: Jack Ellerby Friends of the Lake District on “The Cumbria Dark Skies Project”.
No doubt will tell us about some of his successes to get a reduction of light pollution in the Lake District national park.
Moonwatch with Friends of the Lake District
Just a gentle reminder that the Society will be running a Moonwatch on the Kirbie Kendal School playing fields on Friday November 12th starting at 18:30 and expecting to finish by 21:00. There is plenty of parking in the school car park and overflow, if that is full, at the Leisure centre up Burton Road. This is the Society’s Dark Skies Cumbria Festival that is running from 6th – 14th November .
All welcome. Members of the public have been asked to book on the FLD website, but EAS members can just turn up – you might get asked a few questions by visitors!
Joint Societies Christmas Dinner
Don’t forget the joint north-west societies Christmas dinner. This usually includes the societies from Lancaster & Morecambe, Blackpool and Preston. Date: 16th December. Location: Garstang. There will be the usual after-dinner talk from Prof. Allan Chapman with the meal costing £30. If you are interested, please let the committee know by email with a deadline for monies collection of our December meeting.
Federation of Astronomical Societies (FAS)
You may be aware that the Society gets third party liability insurance through the FAS. In addition, they also produce quarterly newsletters which sometimes contain an interesting article. These are available online, so go and have a look.
Astronomy News – David Glass
Still lots of construction work going on at Boca Chica, Texas, including the installation of the catch arms (‘chopsticks’) on the Mechazilla tower. We posted a link to an animation of what these are for in a previous newsletter – these are key to the rapid turnaround of boosters and starships to get material and personnel into orbit and beyond. There were also two test fires of the Raptor engines on a starship, S20, on 21/10 after proof tests late in September.
These tests involved ignition of both the sea -level optimised and vacuum-optimised engines for use in space, and were separated by a relatively short interval (just over an hour). The sea-level engines are gimballed and have been seen in action already for landing starships. The scale of the engines is seriously impressive – imagine screamingly hot gas at an exit pressure of about 300 bar (4,400 psi) blasting out of them:
No specific date has been announced for an orbital flight involving S20, but it may not be too long a wait.
On 4/10, Blue Origin’s flight NS-18 took four new passengers to the edge of space and back. One of these was William Shatner (the original Captain James T. Kirk for non-Star Trek fans), who at 90 became the oldest person to go into space. See here.
You will notice that I’m not using the term “astronaut” – the IAU changed the definition and I’m not sure that these passengers qualify. The link contains a replay of the build-up, launch and landing – it starts at 2h 26min, but the launch is at 2h 23min.
The flight went smoothly, and they are always fascinating to watch. However, the flight was eclipsed by Shatner’s reaction when he got out of the capsule. They say that seeing the Earth from space changes people…and he was visibly overwhelmed by what he saw (zoom to 2h 43 min in the replay). Here’s an interview where he discussed what he experienced:
NASA Space Launch System (SLS)
Steady progress is being made towards getting the SLS ready for its first flight (Artemis 1), which could be in February 2022. On 22/10 the Orion crew capsule was stacked onto the SLS, which is another milestone:
This now allows the end-to-end testing of the fully integrated rocket, including a full countdown practice. The rocket can then be moved to the launch pad on its mobile launcher for a full “wet dress rehearsal” test where it is loaded with cryogenic propellants and unloaded. Click on image to enlarge.
James Webb Space Telescope
After a 16-day boat trip, the James Webb Space Telescope was unloaded at the Guiana space centre on 12/10 and is being made ready for launch sometime in December (on or around 18/12 is planned):
The launch will use an Ariane 5 rocket, and will get the JWST to the L2 Lagrange point behind the Moon where its position will be relatively stable (think of a weight on the end of a piece of string circling a central point – that’s how gravity will pull on the telescope). For a straightforward description of Lagrange points, take a look here.
16/12 saw the launch of Lucy, a spacecraft intended to explore the Trojan asteroids that occupy space along Jupiter’s orbital path (at Lagrange points!). it should visit eight trojans over a period of about 12 years. These Trojans are thought to be remnants of the material from the earliest days of the Solar system, and studying them will help to plug gaps in our knowledge of how the Solar system formed. For more details of this fascinating mission, take a look at lucy.swri.edu and check out the mission overview in particular.
Currently (29/10) there seems to be an issue with the unfurling of its solar arrays, which hopefully will be resolved soon. Apart from that the spacecraft is healthy.
Imaging the Far Side of Pluto
Astronomers are great at wringing out science from any viable data source. In this case, a team used an image from the LORRI camera on the New Horizons spacecraft to image the far side of Pluto, illuminated only by the very faint reflected light from Pluto’s companion Charon. After some intelligent processing of the data, they managed to detect a high-albedo (i.e. reflective) region in the Southern hemisphere which could be a patch of frozen nitrogen. However, the South polar region had lower albedo, which might point to interesting seasonal phenomena.
The preprint of the research paper on this study is available here.
…and a non-technical summary is here.
The formation of the Moon – Ian Bradley
There used to be three ideas of how the Moon formed: the fission theory where a large mass of the presumed rapidly spinning Earth tore off to form the Moon; the capture theory, where the Earth gravitationally captured a body that had formed elsewhere; the co-creation theory, where the earth and Moon both formed at the same time in a similar region of space.
One indication that the fission theory was correct is that the average density of the Moon was very similar to that of the outer layers of the Earth as would be expected if some of the Earth’s outer layers were ripped off. However, the Apollo rock samples had more refractory elements and less volatile elements than those of the Earth’s surface rocks. Volatile materials boil at relatively low temperatures (900°C) compared to refractory ones (>1400°C). This suggested that the Moon formed from material that was heated to a higher temperature than the Earth so that some of the volatile material boiled away.
However, the consensus now is that none of these three ideas is correct. At a conference in 1974, Donald Davis and William Hartmann proposed an impact hypothesis. It turns out in the subsequent discussion that another group (Cameron and Ward) were independently working on a similar idea. The idea was that the Moon formed some 4.5 billion years ago from an off-centre collision between the Earth and a Mars-sized body, later named Theia after a daughter of Earth goddess Gaia and the sky god Uranus in Greek mythology. Debris from the Earth’s surface spalled off from the collision forming the Moon with most of Theia being absorbed onto the Earth. This ‘graze and merge’ scenario would explain the lack of both volatiles and a lunar iron core, assuming the iron was already in the Earth’s core. It also explains why the Earth spin axis is tilted relative to the plane of the ecliptic. But it left several questions unanswered, not least that simulations rarely gave a Moon with an Earth-like composition and the collision speed had to be improbably low.
Now, new simulations reported in the Planetary Journal (Erik Asphaug et al 2021 Planet. Sci. J. 2 200.) suggest that with faster approach speeds, Earth and Theia do a ‘hit and run’ where they come into violent contact for a short time (30 minutes) before what’s left of Theia escapes. Material passes between the two objects which has time to mix as the surfaces are molten post impact. Crucially, having lost a lot of energy and hence slower, Theia frequently comes back to have another glancing collision with the Earth in typically 0.1–1 million years according to the simulations. This second collision can now be a ‘graze and merge’ scenario as Theia sometimes approaches with the previously improbably low speed. This neatly solves both the composition and speed issues.
The paper goes into a lot more detail on material transfer and mixing if you are interested. No doubt this new model will have some other issues too, but it is an interesting new take on an old model.
Disk spotted round an exoplanet – a moon forming region? – Ian Bradley
Whilst on the subject of moon formation. The Atacama Large Millimeter/submillimeter Array (ALMA) telescope in Chile has found evidence of a possible moon-forming region surrounding a newly forming and recently-discovered exoplanet PDS70c. This orbits the young star PDS70, which is 370 light-years away. The observation, reported over the summer in The Astrophysical Journal Letters ( Myriam Benisty et al 2021 ApJL 916 L2), could lead to important insights into how moons and planets form and evolve within young star systems.
Discs of gas and dust often surround young stars with rings and gaps cleared out by newly forming planets. These planets can also acquire discs of their own, it is believed that moons can form in these discs with a similar effect, more gaps. So far, the process has not been directly observed.
ESO’s Very Large Telescope (VLT) first detected two exoplanets forming round PDS70 by direct infrared images of the system Since then, these giant Jupiter-like planets have been observed using a variety of other techniques. In particular observations in the hydrogen-alpha (Hα) emission wavelength, associated with ionised hydrogen, suggest given the Hα emission that the planets were still accreting material.
ALMA is a millimetre wave telescope that detects the emissions from cool dust grains. The new observations of PDS70 clearly show a disc surrounding the outermost exoplanet, PDS70c, with an outer radius no larger than 1.2 au. They calculate that the disc could contain anywhere between 0.7% and 3.1% of Earth’s mass – enough material to form up to three satellites with similar masses to Earth’s Moon. In addition, the material in PDS70c’s disc is well within the radius where it would be retained by the exoplanet – providing ideal conditions for a moon to form.
The innermost exoplanet, PDS70b, did not display any clear evidence for a circumplanetary disc which could mean that the planet has a far smaller radius within which orbiting material can be retained. Alternatively, PDS70c could have ‘hoovered’ up all the dust as its orbit is better placed within PDS70’s circumstellar disc
The astronomers hope that observations with ESO’s Extremely Large Telescope (ELT), currently under construction in Chile and become available in 2027, could provide direct high-resolution images of the system. This could be a unique opportunity to study the formation of planets and moons which ultimately could improve our understanding of how moons form around young gas-giant planets.
Possible planet detected in another galaxy! – Ian Bradley
There were reports in the archive late last year [ here] of the possible detection of an exo-galactic planet in M51 using the Chandra X-ray telescope. This work has now been published in the peer-reviewed journal Nature Astronomy which, sadly I think, is behind a paywall. Try it.here .
The observers measured the brightness of one of the strongest X-ray sources in M51, with the exciting title of M51-ULS-1. The source is an X-ray binary system, typically containing a compact object, a neutron star or black hole, pulling in gas from a closely orbiting companion star. The material near the neutron star or black hole becomes superheated and glows at X-ray wavelengths, producing a very compact, planetary sized, X-ray source.
The observers noted the detected signal drop to zero for about 3 hours whilst observing the source for 53 hours. They concluded a Saturn-sized planet orbiting the compact object transited the X-ray source. Because the source is so compact, the transit completely occulted the source, totally different to normal exoplanet transits where even a 1% reduction or less is typical. The researchers deduced an orbital distance of about twice the distance of Saturn from our Sun. Unfortunately, the orbital period is estimated to be about 70 years so the gold-standard of a repeat transition proving it is an orbiting exoplanet cannot be done.
The authors also considered whether the dip could be due to:
- Intrinsic variability – but no short duration on-off change of this type has ever been observed before and such a change would be a real challenge for theory
- Absorption by dust in the accretion disk surrounding the compact object – but the spectral signature expected from such an event is not seen in the data
So they are left with the conclusion that they have observed the first ever exo-galactic planetary transit. They go onto say that “the search for extroplanets, planets in orbits located outside the Milky Way, has now become a realistic and practical enterprise.”
Not only do we have exo-planets, we now have extroplanets!
Recent Photos – Ian Bradley
Well time keeps flying by, so another newsletter.
Next meeting will be on October 7th at 7pm when Simon Ebo (UCLAN) will speak to us on ‘The Search for Exoplanets’. The meeting will again be a hybrid one with some people in Kendal Museum, including the speaker, and others on Zoom. Connection details will be distributed shortly. Hopefully, we’ll see a few people in person.
Over the past 18 months or so, when we couldn’t meet at the Museum, the Society has been kept alive and active thanks to the enthusiasm of the members and the work of the committee. We really need to keep the momentum and help the Society to grow. For this, we really need some more people on the committee. At the moment we are operating without either a Secretary or a Treasurer and this has put extra load on each of us. We could also do with a new Chair. Would you be prepared to take on a committee role? No experience is necessary for co-opted committee members, but if you can keep notes and write letters you would be great for Secretary. If you can write cheques and keep accounts you would be great for Treasurer. And anyone who can be the focus for the Society and lead it into the future would make an excellent Chair. Please think seriously about this, and let us know at a meeting or by email if you can help.
Also, don’t forget, contributions to the newsletter from any member are most welcome. They could be stories, historical snippets or photographs.
Ian Bradley, on behalf of the EAS committee.
Joint Societies Christmas Dinner
The Society has been contacted about a possible joint north-west societies Christmas dinner. This usually includes the societies from Lancaster & Morecambe, Blackpool and Preston and can be good opportunity to socialise with others interested in astronomy from outside our area. The provisional date is Thursday 16th December. There will be the usual after-dinner talk from Prof. Allan Chapman with the meal costing £30. At this early stage, this is rather provisional as we all have no idea what the situation will be by December.
Further details will be circulated as soon as we know more.
Astronomy News – David Glass
SpaceX sent four inspirational civilians on an orbital flight (Inspiration4) in a Crew Dragon capsule, launched by a Falcon 9 rocket. This is all proven technology, which has got people to the International Space Station and back. The flight was funded by one of the crew and was to generate support for the paediatric cancer centre at St. Jude Children’s Research Hospital in Tennessee.
The Dragon capsule was launched on 16,th September at just after 8pm EDT to an altitude of about 350 miles, above the orbit of the International Space Station, and splashed down on the 19th. A large window replaced the usual docking hatch to give amazing views. The flight went smoothly, except for issues with the toilet. No such flight is complete without a zero-gee indicator, and this time it was Jude, a small puppy in a spacesuit (replicas are for sale via the hospital).
For a detailed briefing on the flight and the crew, take a look here.
Meanwhile, it’s been construction, construction and more construction at the Boca Chica complex in Texas. Most notably, the massive launch support tower has been finished and a “quick disconnect” arm has been fitted. This will connect to rockets for transfer of utilities such as fuel. Note the stabilisation “claws” at the end.
Later (possibly soon), two enormous “catch arms” will be fitted. The purpose of these catch arms is the stuff of science fiction – it’s intended to catch a descending booster (chopstick style), place it on a launch support and then plant a Starship on it ready for a quick re-launch. For an animation of how it is intended to work, take a look here.
The whole assembly has been nicknamed “Mechazilla”, from a (fictional) giant mechanised dinosaur that went head- to-head with Godzilla (also fictional, for the avoidance of any doubt).
At the time of writing, one of the boosters (BN4) is sitting on a launch support ring on site and is awaiting testing, and Starship SN20 is also sitting in the launch area after having thermal insulation tiles replaced. This is all adding up to a possible launch of a starship into orbit in the not-too-distant future. Keep an eye on the webcams looking at the site (see previous newsletters)!
NASA Space Launch System (SLS)
NASA’s SLS is intended to get people back to the Moon at some point. It is currently in a Vehicle Assembly Building (VAB) at the Kennedy Space Centre (KSC) on a mobile launcher (ML-1), and is being prepared and tested for its eventual first test flight which could be as early as December this year. One recent milestone is an umbilical release and retract test (URRT), which simulates the detachment of umbilicals and their rigid arm from the rocket prior to launch.
The test covered numerous sub-systems to ensure that they worked, and will help to ensure a smooth launch. The video shows that the solid rocket boosters are in place. The mobile launcher allows the rocket assembly to be moved to the launch pad, provides all necessary connections for utilities, communications prior to launch and allows access for personnel and crew. For more details of the test, the rocket and the mobile launcher, have a look here.
The next flight of Blue Origin’s New Shepard is likely to be in October (on or around the 12th), and will carry more civilian paying passengers on a sub-orbital flight into space. The whole flight, from lift-off to capsule landing, lasts about 12 minutes so it’s worth trying to watch it live or recorded. There are rumours going round that one of these passengers is no stranger to space travel across our galaxy neighbourhood, and would become the oldest human ever to go into space. We watch and wait!
Jupiter struck by an object
The possible contribution of amateur astronomers to the field should never be underestimated. One amateur astronomer (José Luis Pereira, Brazil) was filming Jupiter through a telescope looking for potential impact flashes when this happened…
Substantial earthquakes on Mars
The InSight lander on Mars is equipped with extremely sensitive seismometers, and is intended to detect and record marsquakes which can be used to infer the interior structure of the planet (prospectors for oil and gas do this routinely here on Earth). And not just the thud of the next failed ESA lander (as Simon White pointed out!). On the 18th September (Sol 1000 for the lander), a magnitude 4.2 marsquake occurred which lasted for 90 minutes. Two previous events in August hit magnitudes 4.1 and 4.2. The measurements allow the locations of the tremors to be estimated, and will be of use in studying the internal structure of the planet. For further details, including a description of some of the challenges faced by landers such as this, have a look here.
JWST launch date
The James Webb Space telescope (JWST) is a highly-anticipated mission to put a seriously big (6.5m mirror) near- to mid-infrared telescope at the L2 Lagrange point (behind the Moon). It can observe beyond the capabilities of Hubble and ground-based telescopes, and allow new science to be explored (e.g. formation of the earliest galaxies and exoplanet composition to name a couple). Numerous papers are being released on ArXiV discussing how JWST observations can be used for science, presumably as a warm-up for actual proposals for observation time. However, JWST has been subject to many delays, and no launch date was forthcoming – until very recently. A date of 18th December is now proposed, and astronomers all over the planet will be delighted to see it happen. But, it’s better to delay and get it right than see it blow up, so let’s hope it goes soon but safely!
More news from – Ian Bradley
Searching for Ice on the Moon
After many years of little NASA involvement in lunar exploration, NASA has announced the proposed landing site for its Volatiles Investigating Polar Exploration Rover (VIPER) mission due for launch in 2023. The mission is designed to search for possible water ice deposits in parts of craters that are permanently in shadow. Finding usable water on the Moon would provide a valuable in-situ resource for future astronauts and colonies.
The selected landing site had to satisfy four main criteria: Visible from Earth for direct line-of-sight communication; sunlight access for solar power generation; terrain that the rover should be able cross; and for the scientific value, a site expected to contain water ice.
Four sites were considered aworth Crater, Nobile Crater, a ridge that runs between Shackleton and de Gerlache craters, and Shoemaker Crater. The site finally chosen was Nobile crater (85.2°S 53.5°E). A nice video showing this here.
Naturally, something this close to the lunar pole is very hard to see from Earth.
It is hoped that the rover will travel around 20km over 100 days or so investigating the area popping into shadowed areas to investigate before returning to sunlit areas to recharge its batteries. The rover will be automated to some extent in a similar way to the rovers which have been deployed on Mars but the direct line-of-sight communication potential means it could be driven in almost real-time from the Earth!
The rover isn’t large, the usual analogy is that it is the size of a golf cart – about 1.5 x 1.5 x 2.5m. Each wheel can be independently pointed so that it can crab sideways, diagonally, spin on its axis and move in any direction without changing the way it is pointing. It even has headlights! On board will be instruments to find the ice, and also drill down (up to 1m) into the regolith to bring samples to the surface for further analysis. The three spectrometers measure volatiles, like water, and the mineral composition. There will also be a range of cameras to both navigate and image samples.
This could be a really exciting mission.
How to see the same supernova twice!
Well, that is impossible, isn’t it? Once a massive star has exploded, in the process destroying itself and leaving behind a neutron star or black hole, surely it can’t do it again. Well, that is correct, but general relativity has given us the chance to watch one explode again – maybe.
What the scientists have now done is calculate the light paths from the supernova to Earth and realised that a there is a good chance that there is a longer, and therefore later arriving at Earth, fourth path. They predict that this will become visible in 2037 give or take 2 years and appear within the yellow circle. For a simple animation of the light path, see here.
Such measurements as these may be useful as they can be used to constrain the cosmic expansion rate and dark energy models. No doubt, Hubble’s successor will be periodically imaging this cluster to see if the ‘supernova’ reappears.
The Cygnus Loop
For the past year or so I’ve been trying to image the Cygnus Loop supernova remnant. So what is this?
It is situated near one of the wings of Cygnus, the Swan. The large loop is the result of the death of a large star, 12 to 15 times the mass of the Sun, that came to the end of its life some 21,000 years ago. Recent measurements have put the distance of the ‘loop’ and therefore the original precursor star at 2,400 light years, which means that the object is about 130 light years in diameter. The estimated mass of the precursor star suggests that there would be a neutron star produced, but no trace has been detected.
What you see here is the result of the expanding debris from the supernova explosion encountering the material in the interstellar medium, causing this to emit light – obviously UV but also hydrogen emission in the visible and some other elements, predominantly oxygen and sulphur. The whole structure also goes by the name The Veil Nebula with various components names as in the figure. The Western Veil also goes by the name The Witches Broom Nebula.
I said it was large… The angular size on the sky is nearly 3° across. That is 6 times the angular diameter of the full moon, or about the width of your hand held at arms length!
Last year, I attempted detailed images of the Eastern and Western components with my 10” Newtonian telescope and astro-camera, although the seeing was rather poor when I imaged the Western Veil. I also photographed the whole nebula in one image using a telephoto lens and my Canon DSLR camera. The resulting image was in the January 2021 newsletter and it showed the characteristic issue with imaging with a standard DSLR – light from the brightest spectral component, the red line from hydrogen (H alpha at 656nm), is blocked by the filters inside the camera required to get facial colours looking right. To avoid this, this time I used my cooled astronomical camera which is very sensitive at that wavelength. I also reimaged the Western Veil component with my 10” Newtonian telescope to complete my set of the brightest two bits. I should add that each of these more detailed images are mosaiced from three separate images as the field of view of the telescope is too small to get everything in one shot
So the results…
Some recent photographs
Welcome to the September newsletter. I’d like to take this opportunity to those new members who have recently joined us. We all hope you will enjoy the Society.
As discussed last month, we are holding our meeting tomorrow (as I write this) in a hybrid manner – with a live audience in the museum and ‘Zoomed’ in members. We will see how this goes regarding future meetings. As we are having a live meeting, with David presenting space news and recent astronomical information, I decided partly due to time constraints just to focus this newsletter on “what’s in the sky” this month.
Now that the nights are drawing in, I hope you can get out and see the stars when Cumbrian weather permits. It’s always hit and miss. The forecasts aren’t always correct [do I hear a few titters?] but they do give a general idea. Clear Outside (https://clearoutside.com/forecast/54.34/-2.75?view=midday) often shows 100% cloud when in reality, it is just a thin high haze. Whilst that is not great for imaging or viewing faint galaxies, it hardly affects the brighter objects, double stars, the Moon or planets. So you have to look carefully at the details in these forecasts.
Don’t forget, contributions to the newsletter from any member are most welcome. They could be stories, historical snippets or photographs. Just get in contact with an email.
So, to conclude, enjoy the last of the summer and keep safe. Clear skies. Clear Skies.
Ian Bradley, on behalf of the EAS committee.
Astronomy weather forecast sites
They are customizable to your location – the links below are set to Kendal.
This satellite view I find quite useful as it shows the cloud cover for the previous 21⁄2 hours or so. This lets you have an idea as to what cloud is coming … switch to infra-red to view the clouds at night.