astronomy – Page 3 – Open Minds!

Early Warning for Planet Earth: How to avoid mother of all Tsunamis!

Today marks the 4th anniversary of the Indian Ocean Tsunami of December 2004.

The tsunami was triggered by a massive quake that erupted off the coast of Sumatra, and 6 miles deep under the Indian Ocean’s seabed. The estimated 9.1 to 9.3 magnitude earthquake was the strongest in 40 years and the fourth largest in a century. The U.S. Geological Survey later estimated that the amount of energy released was equivalent to the energy of 23,000 Hiroshima-type atomic bombs.

Despite a lag of up to several hours between the earthquake and the impact of the tsunami, nearly all affected people were taken completely by surprise. There were no tsunami warning systems in the Indian Ocean to detect tsunamis or to warn those living on the Indian Ocean rim areas. This cost the lives of over 225,000 people in 11 countries — many of who could have lived if only they had a timely warning to rush inland.

In the past four years, there have been various efforts to set up such early warning systems – as well as effective ways to deliver credible warnings to large numbers of people quickly. These are meant to provide 24/7 coverage to Indian Ocean countries in the same way the Pacific Tsunami Warning Centre has been covering Pacific Ocean countries for many years.

All this is necessary – but not sufficient – to guard ourselves against future tsunamis. For it’s not just earthquakes undersea that can trigger tsunamis. An asteroid impact could trigger the mother of all tsunamis that can impact coastal areas all over the planet.

An asteroid that struck the Earth 65 million years ago wiped out the dinosaurs and 70 per cent of the species then living on the planet. The destruction of the Tunguska region of Siberia in June 1908 – whose centenary was marked this year – is known to have been caused by the impact of a large extraterrestrial object.

When discussing the possible consequences of asteroid impacts on Earth, more attention has been given to the destruction it can cause by such a falling piece of the sky hitting inhabited areas of land. Some people seem to be comforted by the fact that two thirds of the planet’s surface is ocean — thus increasing changes that an impact would likely happen at sea.

In fact, we should worry more. Duncan Steel, an authority on the subject, has done some terrifying calculations. He took a modest sized space rock, 200 metres in diameter, colliding with Earth at a typical speed of 19 kilometres per second. As it is brought to a halt, it releases kinetic energy in an explosion equal to 600 megatons of TNT — 10 times the yield of the most powerful nuclear weapon tested (underground). Even though only about 10 per cent of this energy would be transferred to the tsunami, such waves will carry this massive energy over long distances to coasts far away. They can therefore cause much more diffused destruction than would have resulted from a land impact. In the latter, the interaction between the blast wave and the irregularities of the ground (hills, buildings, trees) limits the area damaged. On the ocean, the wave propagates until it runs into land.

Scientists have been talking about asteroid impact danger for decades. Arthur C Clarke suggested – in his 1973 science fiction novel Rendezvous with Rama – that as soon as the technology permitted, we should set up powerful radar and optical search systems to detect Earth-threatening objects. The name he suggested was Spaceguard, which, together with Spacewatch, has now been widely accepted.

In November 2008, a group of the world’s leading scientists urged the United Nations to establish an international network to search the skies for asteroids on a collision course with Earth. The spaceguard system would also be responsible for deploying spacecraft that could destroy or deflect incoming objects.

The group – which includes the Royal Society president Sir Martin Rees and environmentalist Sir Crispin Tickell – said that the UN needed to act as a matter of urgency. Although an asteroid collision with the planet is a relatively remote risk, the consequences of a strike would be devastating.

The International Panel on Asteroid Threat Mitigation, chaired by former American astronaut Russell Schweickart, urged: “The international community must begin work now on forging three impact prevention elements – warning, deflection technology and a decision-making process – into an effective defence against a future collision.”

This is exactly the message in an excellent documentary called Planetary Defence made by Canadian filmmaker M Moidel, who runs the Space Viz production company. Over the past many months, the film has been screened at the United Nations, on various TV channels and at high level meetings of people who share this concern.

Its main thrust: Scientists and the military have only recently awakened to the notion that asteroid impacts with Earth do happen. Planetary Defense meets with both the scientific and military communities to study our options to mitigate an impact. It makes the pivotal point: “Civilization is ill prepared for the inevitable. It’s not if an impact will happen with the Earth, it’s when!”

In such an event, the film asks, who will save Earth? The 48 minute documentary explores the efforts underway to detect and mitigate an impact with Earth from asteroids and comets, collectively known as NEO’s (Near Earth Objects).

Watch the trailer of Planetary Defence on YouTube:

Neil deGrasse Tyson, Astrophysicist and Director, American Museum of Natural History, in New York, says: “Planetary Defense, the film, is a documentary that explores how ill-prepared we are to prevent our own extinction from asteroid and comet impacts. Filmmaker M Moidel interviewed all the right people, asked them all the right questions, and leaves the viewer scared for our future, but empowered to do something about it.”

Although we have never met, I have been in email contact with M Moidel for several years. I know how deeply committed he is to each of his documentary projects. Working on incredibly tight budgets and performing multiple tasks on his own, this brilliant Canadian has made some eminently accessible, timely and captivating documentaries on ‘big picture’ topics such as the search for intelligent life in the universe, the future of space exploration and, of course, coping with asteroid impacts.

Sir Arthur C Clarke, interviewed on some of Moidel’s films, including Planetary Defence, has highly commended his efforts.

Sir Arthur, whose Sri Lankan diving school was destroyed by the 2004 tsunami, wrote a few days after the disaster:

“Contrary to popular belief, we science fiction writers don’t predict the future — we try to prevent undesirable futures. In the wake of the Asian tsunami, scientists and governments are scrambling to set up systems to monitor and warn us of future hazards from the sea.

“Let’s keep an eye on the skies even as we worry about the next hazard from the depths of the sea.”

From Trincomalee to Mars: The fascinating journey of Percy B Molesworth

It was Sir Arthur C Clarke who first told me, nearly a quarter of a century ago, about a forgotten Ceylonese astronomer who has a Martian crater named after him. His name was Percy Molesworth, and I was fascinated by the story of this man who lived and died in a world so different from ours…and the trails he blazed.

Christmas Day 2008 marks the hundredth death anniversary of this remarkable man who pioneered astronomical observations in colonial Ceylon (now Sri Lanka). Most people in the land of his birth have never heard of him, and therein hangs a sad tale of how the country neglects its intellectual and scientific heritage.

By profession, Percy Braybrooke Molesworth (1867 – 1908) was a major in corps of Royal Engineers, but he is better remembered as one of the world’s leading amateur astronomers at the beginning of the Twentieth Century. From his personal observatory in Trincomalee, on Ceylon’s east coast, Molesworth both observed the night sky and photographed celestial bodies, the results of which he shared with leading astronomical groups in the west. Armed only with a basic telescope, a sharp eye and good drawing skills, he made significant contributions to advancing our knowledge of the heavens at the time.

To revive memories and introduce Molesworth to a new generation a century after his death, I have just written an article in The Sunday Times newspaper, Colombo, which prints it today.

Read the published version of my article: Immortalised on Mars, but hardly known in land of birth

Read full length article, with additional illustrations, on Thilina’s Cafe, the blog of young Sri Lankan astronomer Thilina Heenatigala, a modern-day follower of Molesworth’s steps

In these articles, I weave together material gleaned from a dozen different sources, including obituaries of Molesworth published by the British Astronomical Association (BAA) and Royal Astronomical Society (RAS), and later papers and reviews of the formidable body of work that Molesworth left behind after a short but highly productive life of 41 years.

Sir Arthur Clarke, sitting next to the historic telescope, shows a photo of Crater Molesworth

One of my principal sources is Sir Arthur C Clarke, another astronomically-inclined Englishman who was to settle down in Ceylon decades later, and with whom I worked for over 20 years as a research assistant. Molesworth combined in him several elements that resonated with Sir Arthur -– Ceylon, Trincomalee, night sky observations and Mars. In the years that followed my introduction to Molesworth, Sir Arthur allowed me unrestricted access to his library and archives where I read more about Molesworth, principally from BAA and RAS journals and newsletters.

I also had the privilege of associating the late Herschel Gunawardena, who co-founded the Ceylon Astronomical Association (CAA) with Arthur Clarke in 1959, and served as its first secretary and later president. Herschel told me details of his personal quest for Molesworth, which he had chronicled in an article he wrote in the CAA journal, Equatorial, in 1971.

Others who gave me information or insights into this story include the late Dr V K Samaranayake, who played a part in restoring the telescope in the 1960s, and Fr Dr Mervyn Fernando, a keen amateur astronomer who continues to promote the subject in the local languages through the Subodhi Astronomy and Space Study Centre.

My own connection with Molesworth happened over 20 years ago. In early 1988, while Sri Lanka was engulfed in a brutal southern insurgency, vandals looted the Colombo University dome – by then housing the Molesworth telescope – and removed several parts purely for their metallic value. I covered that incident as a young science journalist working for The Island newspaper, and later wrote a feature article titled ‘The death of an observatory’ (published on 26 March 1988).

Given the political turmoil at the time, it barely made any ripples. I still remember being ridiculed by some for reviving the memory of a long dead man at a time when hundreds of innocent, non-combatant lives were being lost every week due to extra-judicial killings.

Indeed, for much of the past 30 years, Trincomalee has been affected by Sri Lanka’s long-drawn civil war in the country’s north and east. I had planned to visit Trincomalee this year to personally find out the current status of the Molesworth bungalow and tombstone. But that didn’t happen due to the pressure of work and other distractions. I might well do that in 2009, now designated the International Year of Astronomy.

Naming celestial objects is a serious business, carried out by the International Astronomical Union (IAU) through a careful process. There are hundreds of thousands of craters on Mars, but only some of them have names. The Wikipedia has a list of Martian craters which are by convention named after famous scientists and science fiction authors, or if less than 60 km in diameter, after towns on Earth.

Arthur Clarke and Marconi: Waiting for the ultimate phone call

In view of the World Telecommunication and Information Society Day (May 17), I would like to share a short essay I wrote in early April 2008.

Courtesy SETI@Home

Waiting for the ultimate phone call
by Nalaka Gunawardene

Sir Arthur C Clarke was a true believer all his life, who ardently wished for a sign from the heavens. Alas, he never received one up to his death on March 19.

No, this had nothing to do with religion, a notion Clarke publicly dismissed as a dangerous ‘mind virus’. Rather, it’s the prospect of life elsewhere in the cosmos – an idea that always fascinated him, and on which he wrote many stimulating stories and essays.

It wasn’t surprising, then, that this topped the three ‘last wishes’ Clarke mentioned in a short video released in December 2007, on the eve of his 90th birthday.

“I would like to see some evidence of extra-terrestrial life,” Clarke said, wistfully. “I have always believed that we are not alone in the universe. But we are still waiting for ETs to call us – or give us some kind of a sign. We have no way of guessing when this might happen – I hope sooner rather than later!”

Read full transcript of Arthur C Clarke’s 90th birthday reflections, December 2007

Watch the video on TVE Asia Pacific channel on YouTube:

That ultimate ‘call’ never arrived in time for Clarke. And we have no way of telling which of his wishes would materialize first (the other two being adopting clean energy sources worldwide, and achieving peace in Sri Lanka, where he lived for over half a century).

When it came to ETs, Clarke had a good idea of the probabilities of a positive result in his own lifetime. He knew how it had eluded at least four generations of seekers, including the inventor of radio telegraph itself.

Accepting the Marconi Prize and Fellowship in 1982, Clarke recalled how Guglielmo Marconi had been interested in this prospect. He quoted from a letter he (Clarke) had written to the editor of the BBC’s weekly magazine, The Listener, in February 1939: “…On other planets of other stars there must be consciousness; on them there must be beings with minds…some far more developed than our own. Wireless messages from such remote conscious beings must be possible.”

The letter, sent via the then fledgling British Interplanetary Society, ended as follows: “The only time I met Marconi, he told me of his search for such messages. So far, we have failed to find them.”

After a century of radio and 60 years since its inventor’s death, such proof has yet to be found. However, as Carl Sagan – possibly the best known proponent of the subject – was fond of saying, the absence of evidence is not evidence of absence.

Clarke himself is widely attributed as saying: “Sometimes I think we’re alone in the universe, and sometimes I think we’re not. In either case the idea is quite staggering.”

Clarke not only wrote and talked passionately about the subject for decades, but also supported – in cash and kind – various groups engaged in the search for extra-terrestrial intelligence, or SETI.

“SETI is the most important quest of our time, and it amazes me that governments and corporations are not supporting it sufficiently,” he said in a 2006 letter supporting public donations to the SETI@Home project at the University of California, Berkeley.

SETI@Home Arthur C Clarke Tribute page

In the early 1990s, he applauded Steven Spielberg, director of ET: The Extra-Terrestrial (1982) for donating US$ 100,000 to SETI efforts. “It seems only appropriate that Steven…should put his money where his mouth is,” Clarke noted.

Clarke welcomed ET‘s box office success, as it departed from the Hollywood tradition of depicting aliens as malevolent. By showing a highly intelligent being as both benign and vulnerable, the movie stretched the public’s imagination to consider other possibilities. Not all aliens would arrive here to take over our world -– or to serve humanity, medium rare…

But Clarke realised how the vastness of space would make inter-stellar travel difficult and infrequent. It was more likely that signals from advanced alien civilisations would roam the universe at the speed of light.

Together with his long-time friend Carl Sagan, Clarke explored the philosophical implications of SETI – and its eventual success. It should be the concern of every thinking person, he said, “because it deals with one of the most fundamental questions that can possibly be asked: what is the status of Homo sapiens in the cosmic pecking order?”

Clarke believed the detection of intelligent life beyond the Earth would forever change our outlook on the Universe. “At the very least, it would prove that intelligence does have some survival value – a reassurance that is well worth having after a session with the late night news.”

Clarke speculated that ETs may be continuously broadcasting an easily decoded “Encyclopaedia Galactica” for the benefit of their less advanced neighbours. “It may contain answers to almost all the questions our philosophers and scientists have been asking for centuries, and solutions to many of the practical problems that beset mankind.”

He was sometimes ambivalent about the value of such an influx of new knowledge, noting that even the most well intentioned contacts between cultures at different levels of development can have disastrous results – especially for the less advanced ones. He recalled how a tribal chief once remarked, when confronted with the marvels of modern technology: ‘You have stolen our dreams’.

But Arthur C Clarke the perennial optimist continued: “I believe that the promise of SETI is far greater than its perils. It represents the highest possible form of exploration. And when we cease to explore, we’ll cease to be human.”

Clarke’s interest in ETs remained undiminished to the end. In his last media interview, given to IEEE Spectrum in January 2008 from his hospital bed in Colombo, Sri Lanka, he said: “I’m sure the ETs are all over the place. I’m surprised and disappointed they haven’t come here already… Maybe they are waiting for the right moment to come.”

He added, with a chuckle: “And I hope they are not hungry!”

Patrick Moore: 50 years of Sky at Night on the air

The first ever book on astronomy I owned, a pocket guide to the night sky, was written by an Englishman called Patrick Moore.

Armed with the tattered book, I joined night sky observation sessions of the Young Astronomers’ Association. That was more than 20 years ago.

Hormones-on-legs that we all were at the time, we were interested in heavenly bodies at both ends of a telescope. But we couldn’t have had a better guide to the celestial wonders than Patrick Moore.

The same Patrick Moore reached a milestone in the history of broadcasting this month: he has hosted the same show on television for 50 long years, more than anyone else on any subject anywhere on this planet.

The show is The Sky at Night, which started on BBC Television in April 1957.

Sir Patrick Moore Patrick Moore presenting an early Sky at Night programme

The Space Age had not even begun, and television broadcasting was still in its formative days, when a much younger Patrick Moore presented the first Sky at Night in April 1957. But as if on cue, the Soviet Union launched Sputnik One just six months later, triggering the Space Race. Thus Patrick Moore has been our able, dependable and colourful guide to the most fascinating journey in the history of humankind – our species finally venturing beyond its ‘cradle’, the Earth.

But as another populariser of space and astronomy, Sir Arthur Clarke, notes: “Sky at Night has not been just a gee-whiz show of rockets, satellites and other expensive toys deployed by rich nations trying to outsmart each other. At its most basic, it’s a show about exploring that great laboratory within easy access to anyone, anywhere on the planet: the night sky.”

Sir Arthur adds in a special tribute to his long-standing friend:
“By the time the Space Age dawned, Patrick was well on his way to becoming the best known public astronomer in the world. The Sky at Night only consolidated a reputation that was well earned through endless nights of star-gazing, and many hours of relentlessly typing an astonishing volume of books, papers and popular science articles.”

In the 50th anniversary programme, broadcast this month, Patrick Moore traveled back in time to see the first recording of The Sky at Night . He talked to his earlier self about astronomy back in 1957, and discussed how things have changed in half a century. He then time traveled to 2057 where the ‘virtual’ Patrick, saved in the BBC computer, is celebrating 100 years of making The Sky at Night and talks to Dr Brian May about the discovery of life on Mars.

Sir Patrick Moore

Thank you, Sir Patrick, for being our affable guide to the night sky and space travel for half a century. We hope you don’t consider retirement anytime soon.

Read Patrick Moore’s brief history of The Sky at Night

BBC’s 45th anniversary multimedia tribute

BBC Online interview with Sir Patrick Moore

Sir Arthur Clarke’s tribute to The Sky at Night at 50