One Ring To Bind Them

All over the news right now is what is probably going to be #1 in a long list of Things I Wish Had Been Discovered Before I Started Writing The Quiet War And Gardens Of The Sun.

Discovered by the Spitzer space telescope and visible only in infrared light is a vast ring tilted at twenty-six degrees to the Saturn's equatorial plane - the plane in which the more familiar ring system and the inner moons orbit. It's very very big, this ring, circling Saturn at a distance of 13 million kilometres: if you look at Saturn from Earth, imagine that it's sitting inside a ring that is twice the apparent diameter of the full Moon. Factor in the relative distances of the Moon and Saturn, (384,000 kilometres v. the minimal distance, at opposition, of roughly 1300,000,000 kilometers), and you'll realise that this is a very big structure indeed: the biggest known ring in the Solar System

It's very big, but it's also very tenuous. More tenuous than even the vacuum inside electronic vacuum tubes: there are on average twenty grains of icy dust in each cubic kilometre of this giant ring. For good reason, its discoverers are calling it the Ghost Ring. It's no coincidence that it shares the same orbital inclination and distance as Saturn's moon Phoebe; it's almost certainly composed of material knocked off that small and eccentric moon by meteoritic impacts. Phoebe is an odd little moon; not only is its orbit steeply inclined, it's also retrograde - it travels in the opposite direction to the inner moons. Images taken by the Cassini orbiter as it passed Phoebe on its approach to Saturn show an irregular and heavily cratered body, with slivers of bright ice showing through a dark outer crust of carbonaceous material. It's similar in composition to Kuiper Belt Objects, in fact, and was probably captured by Saturn when something perturbed its orbit and it wandered in towards the Sun.


There's speculation that the material in the Ghost Ring has contributed to the distinctive colouration of the outermost of the large moons, Iapetus. Famously, Iapetus is bright on one side and dark on the other, a property spotted by the man who discovered it, Giovanni Domenico Cassini, in the seventeenth century. Now, it seems that the dark sooty material from the ring has been swept up by Iapetus's leading hemisphere over a couple of billion years.


But is the Ghost Ring really the largest ring in the Solar System? Saturn has many other small irregular moons in wide eccentric orbits. Most belong to collisional families and are probably fragments from a larger body that was shattered by some impact after it was captured by Saturn's gravity: the Inuit Group; the Norse Group; and the Gallic Group. Phoebe belongs to the Norse Group. The moons in the Gallic Group orbit even further out. Could they, too, have generated a ghost ring?

A Film I'd Dearly Love To See

Thom Anderson's Los Angeles Plays Itself, an argument assembled from film clips that use actual locations in LA. Plays on the festival/arthouse circuit, will probably never surface on DVD because of copyright issues, alas.

Random Linkage 03/10/09

Dawn Journal: Good performance means a longer stay at Vesta!
'Dawn is celebrating the second anniversary of leaving its home planet by engaging in the same function it has performed most of its time in space: with the utmost patience, it is using its ion propulsion system to gradually modify its orbit around the Sun.'

MESSENGER Gains Critical Gravity Assist for Mercury Orbital Observations
‘MESSENGER successfully flew by Mercury yesterday, gaining a critical gravity assist that will enable it to enter orbit about Mercury in 2011 and capturing images of five percent of the planet never before seen. With more than 90 percent of the planet’s surface already imaged, MESSENGER’s science team had drafted an ambitious observation campaign designed to tease out additional details from features uncovered during the first two flybys. But an unexpected signal loss prior to closest approach hampered those plans.’
(Nice images, despite the glitch.)

Cosmic Rays Hit 50-Year High. Galactic cosmic rays have just hit a Space Age high, new data from a NASA spacecraft indicates.
'"In 2009, cosmic ray intensities have increased 19 percent beyond anything we've seen in the past 50 years," said Richard Mewaldt of Caltech. "The increase is significant, and it could mean we need to re-think how much radiation shielding astronauts take with them on deep-space missions."'

Increase in sea levels due to global warming could lead to 'ghost states'
'Global warming could create "ghost states" with governments in exile ruling over scattered citizens and land that has been abandoned to rising seas, an expert said yesterday.'

Clues To Reversing Aging Of Human Muscle Discovered
'A study led by researchers at the University of California, Berkeley, has identified critical biochemical pathways linked to the aging of human muscle. By manipulating these pathways, the researchers were able to turn back the clock on old human muscle, restoring its ability to repair and rebuild itself.'

Swedish parents win right to name sprog 'Q'
'The parents of a Jämtland boy have emerged triumphant from the Swedish Supreme Administrative Court, aka Regeringsrätten, and may henceforth legally refer to the sprog as "Q".'

More Martian Ramblings

Soon after posting a short note on Paul Davies's proposal about getting to Mars cheaply by staging one-way missions, I ran into my friend Oliver Morton, who pointed me towards a post on his Mainly Martian blog that with takes apart Davies's claims in meticulous detail. Oliver is a Mars-head from way back - his book, Mapping Mars, is essential reading for anyone interested in the history of observation and exploration of the red planet - and his demolition job is pretty comprehensive. Cutting out a return vehicle wouldn't lower the cost of the mission by as much as Davies suggests; if the one-way trip isn't a suicide mission, the Mars explorers will have to set up a permanent base camp under extreme and arduous conditions, and will need continuous resupply from Earth for the forseeable future; the 'lifeboat' argument for space colonisation elides the uncomfortable fact that most people will be left behind. And so on.

All in all, it's a bracing dose of realism. If there is a cheap way of going to Mars, a one-way trip isn't the way to do it. (Still, as an irresponsible SF writer, I feel there's plenty of fictional traction in the scenario. I've already dabbled in it, as the background story of one of the secondary characters in The Secret of Life; now I'm wondering what would happen if, say, there was a privately funded one-way mission to Mars that had to rely on viewers' ratings to keep its astronauts resupplied: a Robinson-Crusoe-On-Mars reality show. Or suppose a one-way mission made a go of it with the help of a substantial resupply programme, and fifty years later their descendants were faced with the bill...).

I do take issue, though, with Oliver's last point:

Human Mars exploration is indeed a fine goal, and it is quite possible that fairly early on there will be some who elect to stay. But the only real argument for doing it sooner or rather than later is the selfish one of wanting to see/participate in it personally. I can appreciate that, but I don't think it's a compelling policy point. There are a lot of other big exciting projects to inspire us -- a new energy infrastructure for the world, the millennium development goals, in pure science the development of telescopes for characterising the atmospheres and possible biospheres of exoplanets.

Yes, going to Mars as soon as possible for personal reasons isn't a compelling reason (even if you are a zillionaire who can fund the entire caper). And yes, there are plenty of other ways to spend the money. But I'm not convinced that funding of expensive space missions diverts essential resources from more pressing problems here on Earth. It's a straw man argument that's been around since the Apollo missions, and there's no evidence that cash cut from NASA funds goes to humanitarian aid or other scientific projects instead; either it goes elsewhere in the overloaded federal budget, or it simply isn't spent. And it isn't as if all that money is blasted into orbit, never to return. Most of it stays right here. It's spent on research and development, on construction of infrastructure, and on the salaries of the thousands of men and women who are involved in supporting manned missions in every kind of way. And if manned missions are cut out of the NASA programme, then all that expertise is lost, and so is the momentum.

The International Space Station is due to be decomissioned in a few years; if it is, that will put an end to the need for manned missions to low Earth orbit. And although there's talk about going to the Moon, we've already been there, and the main rationale for returning is that it would be a staging post or training ground for the Big Leap Outwards. Given that funds are limited, why not start planning and working towards that Big Leap now, with missions to Near Earth asteroids, a round trip around Venus, and maybe a mission to Phobos, rather than a diversion to the Moon? The romantic in me would like to think that kind of thing might be possible in my life time, at least . . .

Xposted to Pyr-o-mania

Gardens Of The Sun, Part Three, Chapter Five

Sri Hong-Owen was walking a transect of the rim forest early one morning, collecting hand crabs for a population survey, when Euclides Peixoto called her out of the blue. He told her that there’d been a little trouble she should know about, back on Earth, and read out a brief official announcement about a successful action against a nest of criminals in Antarctica who had been in flagrant breach of the new regulations controlling scientific research. Survivors had been arrested and transported to Tierra del Fuego; their laboratories had been destroyed.

‘I’m sorry to be the bearer of bad news but there it is,’ Euclides said, not sounding sorry at all.

‘Alder. Is he one of the survivors?’

READ MORE . . .

Another Commercial Break

Gardens of the Sun is amongst the deluge of books published on this Super Thursday. So why not head out to your favourite bookshop, go straight past the piles of stuff by TV personalities towards the quiet calm of the SF section, and do the right thing? Readers in the US might like to know, if they don't already, that The Quiet War is available for download to their Kindles.

I'll be posting the last extract from Gardens of the Sun tomorrow: a long chapter that will bring us to the end of the third section, and the midway of the book.