Planet killer: Ex-army officer's Welsh space-rock mission
Tunguska, Chelyabinsk... Powys
Posted in Geek's Guide, 6th July 2015 13:37 GMT
Geek's Guide to Britain As I approach the Wales-England border, the rolling Herefordshire countryside sharpens into steep hills and narrow valleys. Powys is a county covering a quarter of Wales, but it is home to just 133,000 people, making it the least densely populated area of Britain south of the North Yorkshire moors.
Limited population means few buildings and roads and therefore lights – with their annoying visual pollution. It's therefore a perfect place from which to watch space from a telescope and look for potentially planet-killing asteroids.
I’m travelling to a privately run observatory dedicated to tracking Near Earth Objects (NEOs): it is known on local signs as Canolfan Gwylio’r Gofod – The Spaceguard Centre.
Arguably the best, last hope of Britain and the world, Spaceguard is the inspiration of a single man: an ex-army officer specialising in surface-to-air missiles called Jonathan Tate.
It also turns out to be a fun and absorbing tourist attraction for all the family. Once over the border it’s not long before I’m in Knighton – a rare town in the Powys expanse, where I find a brown sign that directs me to the site.
After several minutes’ ascent and just as the single-track lane levels out, another sign directs me on to a farm track. Through a farm gate, the summit reveals a collection of red-brick buildings topped off with a lopsided metal cylinder, used to house a large telescope.
At 417m (1,368 feet) above sea level, the Spaceguard Centre would be a fine place to survive the tsunami that would result from a sizable asteroid hitting the Atlantic, and – given its remote location and good sightlines downhill – a decent place to hole up for the breakdown of civilisation which would probably follow, even in Wales.
The aim of the Spaceguard Centre is to help stop near-earth objects (NEOs) hitting Earth in the first place: Spaceguard in June participated in Asteroid Day, a global project to raise awareness of asteroids. This year’s event took place on the anniversary of the 1908 Tunguska event, the largest asteroid impact on Earth in recent history.
To Powys and beyond: Spaceguard's telescope outbuilding occupies a commanding vantage point
Asteroid Day came with a declaration signed by some of the big names of international space and science calling for greater technology to track near-earth asteroids. Among the signatures were those of Professor Brian Cox, Canadian ISS commander astronaut Chris Hadfield and Jill Tarter of the SETI Institute.
As part of Asteroid day, Spaceguard ran a free open afternoon on June 28, but I dropped in before that and was hosted by Tate. The tour is basically a 90-minute interactive lecture by Tate, armed with props including a planetarium, real meteorite samples and a 2.5 ton telescope. Visitors can ask questions as and when they like: if anyone knows the answer, it is likely to be Tate.
He walks us around the centre’s well-equipped exhibition room, using its items to make things clearer. He starts by talking about the formation of stars and planets with the help of a model solar system and a few minutes in a small planetarium, then zeroes in on asteroids and comets – bodies small enough to be wrenched out of a regular solar orbit.
He explains that 100-150 tons of material hits the Earth’s atmosphere every day: mostly dust, some of which causes shooting stars. Tate is interested in the bigger stuff that either falls to Earth or explodes – or “pops”, as he cheerily puts it – in the atmosphere. The NEO that burnt up over Chelyabinsk in Russia in February 2013 was around 20 metres across and popped 30-45km up, but it still injured 1,600 people by causing a shockwave which blew out windows.
If the Tunguska event – the larger NEO that exploded over in Siberia in 1908, levelling hundreds of square kilometres of forest – had taken place over south-east England, it could have demolished London and damaged buildings across the UK. A prehistoric NEO turned 300 sq km of Middle Eastern desert to glass. To illustrate all this, there is a glass case of off-planet samples, which Tate shows off to wide-eyed children and grown-ups alike.
Big bang theories
Some NEOs would have even more, er, impact. A 1km-wide rock would kill a fifth of the Earth’s population and set civilisation back to the Middle Ages, at least until surviving Register readers were able to rebuild the internet. A collision between Earth and an object 5km wide would cause massive climate change as well as a very big hole, sending us and much of the rest of life on Earth the way of the dinosaurs – this is probably what wiped them out. Summing up the full range of Earth-bound objects, from harmless shooting stars to the end of life, Tate tells us: “We’ve got a pretty big toy-box to play with.”
First, Tate provides the good news: the last 20 years have seen around 95 per cent of NEOs more than a kilometre in size spotted and tracked. Their orbits have been calculated, and none are coming this way for at least a century. And it gets better – if and when we spot one that is, there are plenty of ways to move them out of our way.
The Spaceguard Centre, with expansion for Project Drax
The nuclear option taken by Bruce Willis in the 1998 film Armageddon is not recommended by Tate: blowing up one large, predictable object would produce thousands of unpredictable smaller ones. Far better to nudge the NEO than nuke it, he tells us, as red kites and buzzards wheel outside. We might use ablation – heating up part of the object, causing it to vent vapour so it propelled itself like a rocket motor – or park a large spacecraft near the object, exerting enough gravity to shift it away from a collision course.
For a comet that rarely comes close to the Sun, we might only have a couple of years to change its orbit – but most NEOs are asteroids, where humanity should have decades to get organised. “The bottom line is, there is nothing here we can’t do,” Tate says, adding that the dinosaurs simply lacked a space programme. The bad news is that we aren’t putting in the ground work – at least, not enough of it. While astronomers have tabs on most of the biggest NEOs, work has barely started on those that could take out a city. An asteroid of 150 metres would reach the ground at as much as 50,000 mph – triple that if it were a comet – continue into the crust then explode, causing a round crater 3km wide.
At the end of 2014, NASA’s Near Earth Object Programme had 11,949 asteroid NEOs on its database, with just 861 of them larger than a kilometre across. Of those between 140m and 1km, Tate says we probably know of just five per cent to 10 per cent of the total. At the current rate of discovery it could take more than century to spot and track the rest. But things are looking up. The US is already involved, through Nasa’s Ames Research Centre and the US Air Force Space Command, with the NEO issue being championed in Washington by US congressman Dana Rohrabacher. The European Space Agency is also increasingly contributing to the field.
So how about Her Majesty’s Government? “Doing nothing. Not a terribly bright idea, current British government policy,” Tate tells us.
Inside Spaceguard's observatory
In 2000, the UK government commissioned a comprehensive report on NEOs and decided to give the National Space Centre in Leicester £300,000 to build an exhibition and website, designating it as the National Near Earth Objects Information Centre. The Spaceguard Centre recently took over the national information centre job, but is also part of the global effort to track NEOs. Spaceguard itself is a classic product of British inspiration and inertia. Tate in 1996 proposed that the Ministry of Defence establish a centre to study the threat posed to the UK by the impact of an asteroid of comet.
He claimed support from Arthur C Clarke and scientists including Gene Schoemaker – who helped discover comet Comet Shoemaker–Levy 9 that broke up and collided with Jupiter in 1994 – and Professor Edward Teller, who was an early member of the Manhattan Project which developed the atomic bomb in the US.
The MoD passed on his proposal, but not the Department of Trade and Industry, which funded further study and established a task force to assess the threat. That study led to nothing much happening, so Tate set up the Spaceguard Centre, opened in 2001 by Sir Patrick Moore. It was equipped with private money, although it received a £1,400 award from the Particle Physics and Astronomy Research Council (PPARC) in 2002.
Spaceguard is today home to two large robotically controlled telescopes, used by Tate to confirm other people’s NEOs spottings. Moving us across to his control centre, he demonstrates the process: a progression through three time-separated images of the same patch of the night sky where a NEO is expected, which makes it easy to spot what’s moving. Software automatically prepares reports for the International Astronomical Union’s Minor Planets Center, helping to calculate orbits.
For those about to observe rock
As a finale, Tate leads us out of the exhibition room into the tall circular space which houses one of these two telescopes. After climbing some steps, we see a 13-inch-lens, 2.5-ton refractor telescope on a hydraulically powered floor – which Tate demonstrates while we’re standing on it – and a rotating roof. Another 14-inch-lens telescope sits inside a white dome opposite the observatory’s car park, although this isn’t part of the tour.
It all sounds a little Bond villainesque, as does the centre’s Project Drax, named after Moonraker’s missile-obsessed baddie. Having said that, most Bond villain projects don’t include “possibly the survival of the human species” in an online mission statement – but Project Drax does, because all being well, it will let Tate search for new NEOs, as well as confirm those already seen.
Back down the stairs, he shows off pictures of the telescope he will use under Project Drax. In June 2009, the Spaceguard Centre took ownership of a 24-inch-lens, 7.5 ton Schmidt Camera, built in Newcastle in 1950 and later moved from Cambridge to Knighton. It was donated by Cambridge University’s Institute of Astronomy, as light pollution in Cambridgeshire meant it was no longer viable. When it is installed in dark-sky Powys, it will be the largest telescope in Wales, capable of observing five degrees of sky at a time.
Sample from Chelyabinsk
Since then, Tate and a group of volunteers have largely built the housing for the new telescope and installed its base assembly: visitors can see this to the right of the centre’s entrance. To install the telescope itself – currently waiting shrink-wrapped in plastic – and the technology to work it, the Spaceguard Centre needs the final third of the project’s £97,000 budget.
If money were no object, Tate reckons work could be finished within months. But now, our tour exits through the gift shop – because this, along with donations and entrance fees, is how the Spaceguard Centre is raising the rest of the money to set up what will be the only dedicated asteroid tracker outside of the United States.
Tate encourages us to dig deep, not least because he has stationed a sniper outside to take out non-payers. He’s probably joking.
The location of the centre on top of a hill in a remote part of the country means that getting here is likely to take a bit of planning. There is no catering on-site, although there are cafes and inns including the Horse and Jockey down in Knighton. The town also offers the Offa’s Dyke Centre, a museum about the giant earthwork which marked the old border between Wales and England and the long-distance path that now follows it. Other nearby attractions include the scenic Elan Valley estate further into Powys, the Red Kite feeding station near Rhayader and the Small Breeds Farm Park and Owl Centre in Kington in Herefordshire.
Knighton, which also has a branchline train station, is just 17 miles west of the handsome and historic town of Ludlow, a tourist favourite. It is also less than 75 miles from population centres including Birmingham, Stoke-on-Trent and Cheltenham.
It’s worth allowing some extra time to get to the Spaceguard Centre, as the local roads are more scenic than speedy. But it is worth the trip. Visitors learn about the problem of NEOs from someone who devotes his life to the subject and can explain it in an informative and drily humorous fashion – in a way that isn’t likely to scare children, although it may confirm adults’ fears about the UK government.
And by paying to visit, you also become a small part of the solution. ®
By car: Knighton is on the A4113 from Ludlow and the A488 from Llandrindod Wells to Shrewsbury. The Spaceguard Centre is reached by turning off the A4113 just east of the town centre, and driving south (and up) Llanshay Lane for 1.5 miles, then west on a farm track. There are clear signs at each junction, which are to be trusted more than your satnav. Public transport: Knighton train station is about 50 minutes from Shrewsbury on a stopping service which runs four times each weekday and reaches Swansea three hours later. You will then have a long walk uphill to the Spaceguard Centre – it may be better to get a cab.
Entry is by conducted tour only, and costs £7 for adults, £4 for children aged 5 to 15. Tours run on Wednesdays, Thursday, Fridays, Saturdays and Sundays at 2pm and 4pm from October to April, and also at 10.30am from May to September. Although it is usually possible to turn up at one of these times on spec, the centre recommends you phone first in case it has a block booking. Group tours can be arranged at any time (including evenings, for £1 extra per person), with a minimum charge of £48.