Welcome to the February newsletter.
Cumbrian clouds and rain have lived up to their reputation the past month with very few clear evenings. Just glimpses every now and again. I guess the forecast for the next month is more of the same! My fault as I’ve acquired some narrowband filters and a mono-astrocamera!
Last month, we had an excellent talk by Prof. Lionel Wilson on Venusian vulcanology continuing the series on volcanos of the Solar System. Hopefully, we’ll get Lionel back for another talk in the next year or so, as he himself said, there are other volcanic systems out there… Thinking of the programme, David Glass has done an excellent job on the programme for our 1st Thursday of the month meetings for the rest of the year.
So hopefully we’ll have some good meetings and with luck and a vaccine, maybe even back in Kendal Museum.
Don’t forgot that the Cumbria Dark Skies Festival starts shortly (Feb 5th to 21st) with many interesting online talks (many only £3.50). Further information can be found here.
A lot of this is being driven by Friends of the Lake District (FoLD) as part of their dark sky initiative. EAS is involved with FoLD, mainly Clive and I, in their Dark Skies project as are many other Cumbrian astronomy societies. There are things we as individuals can do to reduce light pollution (LP) and protect our darkish skies – see here for a few tips. If you see any excessive light source in the Kendal area, for example through bad positioning, angling or just on all the time, let me know and I will pass that information on to the FoLD team. They are currently employing consultants to do an LP survey before they tackle individuals or companies to try and get some changes. The ‘Environmental Act 1990; law on statutory nuisance’ covers LP nuisance, so things can change.
One final note on LP. There is a lady in Penrith (which has no astro society) trying to get light glare reduced. LP is surprisingly bad round Penrith with some big industrial sites by the M6, several brightly lit quarries and nearby Center Parcs. She was unsure how to go about getting LP reduced and various local societies (Cockermouth, Carlisle, EAS) had a Zoom discussion with her. The bottom line was that ultimately, locals have to drive change. Since then, I’ve had a few email exchanges with her. She has written to the local paper (The Cumberland and Westmorland Herald). This produced supportive replies from locals and I contacted the paper and sent them an image of light pollution over Penrith taken from Orton Fell. However, being a realist, it is difficult for us as a society to do much, being Kendal based, but if you happen to live in that direction, are affected by LP and willing to talk to her, I’m happy to put you in touch.
Ian Bradley, on behalf of the EAS committee
Perseverance Mars rover landing – Ian Bradley
Don’t forget that NASA’s ‘Perseverance’ Mars rover is due to land on Mars on Thursday, February 18th at about 20:55 GMT in Jezero Crater after another ‘7-minutes of terror’; entry, parachute descent followed by the final sky crane lower onto the surface. NASA TV is live from 19:15 GMT. There’s a nice animation here. Here’s hoping for another successful landing. As John McNamee, project manager for the Mars 2020 Perseverance rover mission puts it, “Don’t let anybody tell you different – landing on Mars is hard to do.” With luck, we’ll soon get an image like this on the right which I believe was the first mastcam image taken by Curiosity inside Gale Crater.
Why Jezero Crater? On ancient Mars, water carved channels and transported sediments to form fans and deltas within lake basins. Images suggest that the 750km diameter Jezero Crater in the Isidia Planitia region was at one time filled with water forming a shallow lake. It is believed that such a wet region could have been environmentally favourable to life. A river flowed into this lake off nearby highlands, dumping eroded material to form a delta. The landing site in Jezero Crater was chosen to be near this delta because orbital spectral data show that some of the sediments here have minerals that indicate chemical alteration by water – clays and carbonates. A great place to fulfil the Mars 2020 mission’s science goal of studying a potentially habitable environment that may still preserve signs of past life.
Astronomy News – David Glass
The much-anticipated test flight of Starship SN9 mentioned in the December newsletter looked like it would go ahead early in January. It didn’t, but it is now likely on 1st – 3rd February. Anyone checking in on the webcam sites around Boca Chica would have seen lots of activity in the run-up to this, and several reasons are behind the delays including technical issues, poor weather and bureaucracy.
SN9’s Raptor engines were test-fired initially on 6/1/21, followed by an astounding three static fires with no intervention on 13/1/21 (18:28, 20:22, 21:36 GMT). There’s a great compilation video of this event.
After all this testing, two of the Raptor engines needed to be replaced because of minor damage. There was another static firing on 21/1/21 and 22/1/21 GMT, and a “wet dress rehearsal” for launch 28/1/21, with delays to launch due to adverse weather and other issues. Since then, SN9 has been sitting on the pad awaiting FAA approval for launch after a regulatory hold-up prevented a launch on the 28th.
The issue which caused Starship SN8 to crash is believed to be low fuel tank pressure during the latter stages of the flight. The solution to this for SN9 is to pad the tank with helium, which will help to maintain the tank pressure as it is emptied during flight. However, this is only a temporary fix while other permanent solutions which add less mass are explored. Another item of interest was pressure-tested at the site on 26/1/21. A new fuel storage vessel, named Starship 7.2, has been built out of thinner (and therefore much lighter) stainless steel plate. This was filled and pressurised with liquid nitrogen, and held at pressure for 3.5 minutes. The test was judged to be a success, and the vessel didn’t burst dramatically like its predecessors. The new design represents a significant saving in mass, which means more payload can be carried.
And within the last few days, Starship SN10 was moved into position for testing and launch…
Blue Origin’s New Shepard launch vehicle is intended to transport payloads to sub-orbital altitudes (i.e. into space and straight back down again) – including scientific instruments and paying passengers. An impressive test (no 14) of the vehicle and a new 6-seat passenger capsule was conducted on 14/1/21, from their West Texas launch site. The capsule includes large windows to allow great views for the passengers (referred to as astronauts – well technically they are!), and a new feature which allows the whole assembly to rotate slowly to give everyone the best views was demonstrated during the flight.
The test was successful, with the capsule separating from the launch vehicle and reaching an altitude of just over 66 miles (351,000 ft approx.). The launch vehicle then did a successful powered landing, and the capsule landed later on its parachutes with impact cushioned by retro-rockets. There was one passenger on board, “Mannequin Skywalker” who is a veteran of these test flights, and additional cargo of 50,000 postcards from students around the world. Highlights of the flight are here.
If that has inspired you to buy a ticket for this 11-minute flight with forces of up to 3g and a few minutes in microgravity with stunning views, take a look here.
NASA’s Space Launch System (SLS) was put in place on its test facility at Stennis Space Center near Bay St. Louis, Mississippi towards the end of 2020. After a “wet” dress rehearsal in December, the time came for a static fire test of its four RS-25 engines (last used on the space shuttles) on 16/1/21. This was due to last for around 8 minutes, which is the full duration of a launch. However, certain safety parameters were set conservatively and the test was aborted after about a minute. In spite of this, a huge amount of data was gathered on the performance of the system which will guide future tests. SLS will eventually be used for the Artemis 1 mission which is heading for the Moon.
The test itself was particularly impressive, with high-resolution cameras giving views from many different perspectives. The whole live stream is available here (2h 20 min!), but I recommend that you skip to 2h 00min to get the build-up before the test and the test itself. Note the dramatic use of water (>300,000 US gallons/min) to quench the exhaust, which really gives a feel for the power involved. funniest live comment: “Shut up about SpaceX!”
At the other end of the scale for rockets, Virgin Orbit successfully put 10 small satellites into low-Earth orbit using its LauncherOne system on 17/1/21. This is a converted Boeing 747 (in Virgin livery) which took the rocket up to 35,000ft altitude before releasing it to fly into space. This system has the advantage that it can be deployed from anywhere that has the right runway length and facilities. I won’t discuss the ethics of small satellites in orbit, especially involving an aforementioned operator.
Photosynthesis on Exoplanets?
We all know that photosynthesis, where complex molecules are built up from simple ones using sunlight and chlorophyll, is essential for life on this planet. With the discovery of exoplanets around red dwarf stars in the right orbits for liquid water to exist, a logical question is whether the spectrum from these stars could sustain photosynthesis as we understand it. A paper released on ArXiv in January suggests that it can.
The figure below shows the spectra of the Sun and different types of red dwarf star. It’s clear that the spectra of the red dwarfs all peak at longer wavelengths, i.e. would appear redder to the human eye. The research team reproduced this spectrum and the intensity of light expected on exoplanets that could potentially support life, and subjected different types of extremophile cyanobacteria to it. One (Chlorogloeopsis fritschii PCC 6912) can survive in hyper-salty lakes and very hot thermal springs. Another (Chroococcidiopsis thermalis PCC 7203) is found in a wide range of hot/cold and wet/dry environments. A third (Synechococcus sp. PCC 7335) was originally isolated from a snail shell found in an inter-tidal zone, and can withstand changes in light levels as well as wet and dry conditions. A fourth (Synechocystis sp. PCC 6803) was not expected to photosynthesise under these conditions and was used as a control.
The results? PCC6803 and 7203 were able to photosynthesise. PCC6912 and 7335 (the control) were just about able to photosynthesise, using the low levels of light that they required at wavelengths away from the spectral peaks. This is because the more capable bacteria use particular types of chlorophyll that can make use of the light wavelengths available.
This does offer the potential for biological process that we understand to be present on habitable exoplanets around red dwarf stars. If chlorophyll (or something like it) is involved in these processes, then perhaps ways of detecting such activity could be devised. For example, deficiency at the right wavelengths in the reflected spectra from these exoplanets could be due to absorption of light by chlorophyll. This is a challenge for the extremely large telescopes being built or planned – watch this space! The ArXiv paper is here.
Waving at Saturn in 2013 – Graham Fell
The image is an early one of Saturn taken by Hubble. A few years ago, NASA sent a probe to Saturn called Cassini and it sent back some fantastic images over a period of several years. Google Saturn Cassini images and you will find images that are truly wonderful and are Art in their own way.
The greatest picture taken by Cassini was taken from the other side of Saturn looking back towards the Sun, with Saturn blocking out the Sun, and Earth as a single blue pixel in between the rings. Here it is, a genuine untouched real photo.
Now NASA told us exactly when this would happen and so it was that many people waved at Saturn at the moment the picture was taken. So, I (and many others) are in that pixel! Google “Waving at Saturn”, click on images and the third image is taken from Kendal Castle and the idiot at the back in shorts and a silly hat is me!
If any of you use the Helme Chase Surgery on Burton Road, then you may know Carol in the pinkish red sweater at the front. She is a nurse there.
Bearing in mind that (obviously) there was no-one aboard Cassini, I find it amazing that the NASA scientists could work out that picture and then get Cassini to be in the right place at the right time! Kendal was one of the few places in the UK that decided to “Wave at Saturn” and there were about 400 locals that went up to the Castle to witness it. I am immortalised forever in that picture and my naked legs will still be visible long after I disappear off this planet. It was July 19th 2013.
This was a moment for the Society to be proud of and was one of many outdoor events organised by Stuart Atkinson in the earlier days of the Society.
A rather serendipitous observation whilst checking the focus on a camera. Uranus was well placed and… to my surprise I could see three ‘star-like’ objects round the planet and yes, some of them were the moons. Oberon, Titania and Ariel were visible plus a star. Ariel is almost lost in the glare, just a slight blip partially separated, from Uranus. There are another two brightish moons completely lost in that glare.