Update 25th August 2106

by Duncan lunan - 12:41 on 26 August 2016





Update 25th August 2016


There was very exciting news yesterday from the European Southern Observatory. (It came out as a press release the night before, but was embargoed until after a press conference yesterday evening, which they brought forward to midday.) Between January and the beginning of April, a team of astronomers conducted a search programme called Pale Red Dot (by analogy with Carl Sagan's description of Earth from Voyager 1 as a 'Pale Blue Dot'). The object was to seek a planet orbiting Proxima Centauri, the nearest star to the Sun at 4.2 light-years. Proxima is a red dwarf star, invisble to the naked eye from here, and it orbits at 0.1 light-years from the bright double star Alpha Centauri, whose smaller component has a planet which is earthlike, but orbiting too close to be habitable.


Alpha Centauri A could in theory have an earthlike planet, and an imagined colony mission to one was the theme of Part 1 of my first book "Man and the Stars" (1974). None has so far been detected. As a red dwarf star Promima Centauri might seem a less likely candidate to host a habitable world, but artists and writers have persisted in imagining one there. The first story of Sydney Jordan's classic Jeff Hawke comic strip was set on a planet of Proxima Centauri, and David Hardy produced some well-known paintings of one for "The Challenge of the Stars", his 1972 book with Patrick Moore.


Amazingly, the Pale Red Dot search has found definite proof of one: a planet with 1.3 times the mass of the Earth, orbiting with a period of 11.1 days at a distance of 7 million kilometres (4.5 million miles), only 18 times the Moon's distance from the Earth but well within the ecosphere, the distance from the star at which liquid water could exist on a planet with a suitable atmosphere.


Having a potentially life-bearing planet so close to us will obviously stimulate much more study, and having a potentially habitable one so close will focus new attention on the possibility of interstellar probes, revived only last year by Stephen Hawking and others (Project Starshot). But one other fact about it is of great interest: so close to the star, it will probably have a trapped rotation, keeping the same face always towards it. Proxima Centauri is a flare star and the sunward face will frequently be exposed to intense ultraviolet radiation and x-rays, but life might be sheltered in a deep valley on the 'twilight zone' – precisely the situation described by the 12th century Green Children of Woolpit, in the extraordinary story which led Richard Burton, 500 years later, to suggest they might have come from another world.


The children were unquestionably human. In my book "Children from the Sky" (Mutus Liber, 2012), I believe that I identified the green girl in the historical record and traced her descendants down to the present. The girl herself specifically said that the green colour had nothing to do with green blood, genetic engineering or any of the esoteric suggestions which have been put forward, but was vegetable dye, apparently some form of protective coloration, because everybody wore it in the land or world that she came from. The children's sudden appearance in East Anglia, apparently in July 1173, seems to have been a matter-transmitter accident, in which they had accidentally been returned to Earth from an experimental settlement on a planet with a trapped rotation.


A planet with a trapped rotation would not have magnetic field, and in 1173 the Earth's magnetic field was particularly disturbed by solar activity. When I put that to my friend Andy Paterson, he was able to figure out from that how it might have worked. The system he described could be used to link any two earthlike planets, in a broad band of distance around the disc of the Milky Way. From a planet orbiting Proxima Centauri, from which the target Earth could be seen and studied, maybe it would have been even easier. My colleagues and I put a lot of work into modelling ('world-building') the green children's planet, based on the few points of their description which have come down to us, but if we'd known about Proxima B, let's face it, we'd have assumed that was it.


That's not to say that Proxima B definitely was it. The children's world had a surface gravity close to Earth's, because they were able to run when they got here, so a planet with 1.3 Earth masses would have to have significantly lower density to match that. I suspect it may not be long before Proxima B is imaged and we get an estimate of size from which we can work that out.


Also, if Proxima B has a large moon, they would orbit around their common centre of mass (the barycentre) and might well have mutually trapped rotation, rather than facing the star, which might make the planet more hospitable to life (apart from the radiation hazard). But that might not be a situation which could last. Satellites of satellites are unstable, and even Mercury and Venus are too close to the Sun to have moons, due to what Isaac Asimov called 'the tug-of-war factor' which would cause them to crash or be driven off into space. Probably that would apply to Proxima B as well, and I imagine it won't be long before somebody works it out for sure. One way or another, it gives us a very exciting range of possibilities.


Back in this world, last week Linda and I made a trip to Sutherland to visit my mother in the Oversteps care home in Dornoch. We had excellent weather for the trip and found Mum in good form – she will be 103 in November and is still fully alert, if a little confused at times. There were no problems with the journey, most of which was by Gold Coach from Glasgow to Inverness. We were very well looked after at the Amalfi guest house, and had a family meal at the Sutherland Hotel with my sister Mary and her husband Dave Goulder, along with my nephew Alasdair, his fiancée Donna and her daughter Nadine; we had another good meal at the Royal Kashmir the following night, but as it's recently changed hands and the menu is mostly Bangladeshi I suspect it will have a new name by the time we go back (for the wedding next July).


The only slight problem was that while we were away, someone cloned my Facebook account and tried to use it to raise money, while I was offline. A lot of people spotted it and Stewart Horn reported it to Facebook, who promptly investigated and took it down – thanks to them and to Stewart, it was all over almost before I knew about it.


Since we got back the biggest thing has been preparing for the launch of my new book "The Elements of Time" by Shoreline of Infinity, on September 7th. It's a new collection of my time-travel stories, and details are on my website and Shoreline's, where the book can be pre-ordered. The launch will be at the RSAS Barassie Works Club, 4 Shore Road, Troon, Ayrshire KA10 6AG, with music, readings, and a question-and-answer session with Sydney Jordan, who has illustrated all of the stories and provided the cover. I received the first copy this morning (looking great!), just in time to talk about it during a 2-hour interview with Paranormal Radio.


At the Astronomers of the Future Club tonight, Thursday 25th August, at 7pm in the RSAS Barassie Works Club, I'm going to give an introduction to Sydney and his work so that the members will be prepared for his visit. Normally I'd have put out my monthly astronomy column with all this, but I rely on Astronomy Now for updates and for some reason this month's issue is late (arrived this morning, not opened yet). I have provided the usual mid-month version to Troon's Going Out and I'll get an updated one out before the end of the month.


I have another book review to do for Shoreline of Infinity by then, and another book for review has just arrived from Interzone. I had a message recently from my old friend, the poet Donald Saunders (who did the production edit for my book Starfield in 1989). He says he's enjoying retirement – I wonder what that is?





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