Fate of world's biggest telescope in Canada's...
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Jan 19, 2015  |  Vote 0    0

Fate of world's biggest telescope in Canada's hands

Canadians want to use a basketball-court sized telescope to hunt for alien life. Will Stephen Harper let them?

SIDEBAR

Five mysteries to be solved

Some of the space questions scientists are eager to crack with the TMT and other new telescopes:

What is dark matter? Based on observations of galaxies, astronomers have inferred that 22 per cent of the universe is so-called “dark matter,” which they know must exist but can’t detect directly; telescopes can help fit models to reality.

How do the universe’s most extreme objects behave? Gamma-ray bursts are the most energetic explosions in the universe, achieving energies beyond anything possible with an earthly particle accelerator. Because these events are so rare, astronomers must look over great cosmic distances to find them.

What do the earliest galaxies look like? By looking deeper and deeper into space, astronomers are able to look further back in galactic time. In particular, astronomers are eager to take a “census” of the galaxies formed in the first few hundred million years after the Big Bang.

What is the relationship between galaxies and black holes? Do all large galaxies have black holes at their centre? Astronomers want to look more closely at the black hole in the centre of the Milky Way, in particular.

To be determined: Many scientists say they are most excited to stumble across findings we can’t even imagine yet.

Source: TMT Science Advisory Committee

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MAUNA KEA, HAWAII — Belly buttons are one of three spiritual centres of the body in native Hawaiian tradition. Mauna Kea, the dormant volcano that looms over Hawaii Island, is considered the island’s navel: it connects the people and the land to the heavens, as if by umbilical cord.

At 2,800 metres above sea level, York University science dean Ray Jayawardhana pulls into a parking lot and begins rolling his suitcase toward a series of low-slung buildings. He spots two men heading toward one of the fleet of SUVs parked nearby.

“Have a good night,” he says.

That phrase means much more up here. Jayawardhana and nearly every other visitor are astronomers on their way to or from the woozy heights of Mauna Kea. At the mountain’s summit are four of the largest telescopes in existence.

Jayawardhana and University of Toronto graduate student Lisa Esteves have won two coveted nights at Japan’s Subaru telescope to hunt for water in the atmosphere of an alien planet, a “Super Earth” called 55 Cancri e that orbits a star 40 light years away. Finding it would be a significant step in the search for life elsewhere in the universe.

Yet the proposal is an ambitious one, even for an observatory like Subaru.

“Tomorrow night we will be pushing the limits of one of the world’s biggest telescopes,” Jayawardhana says inside. They will need to have a very good night.

A new generation of telescopes is underway, technology that will exponentially boost our power to scour the skies for signs of life and probe other distant galactic mysteries.

Three teams are racing to finish theirs first. The Giant Magellan Telescope will be constructed in Chile’s Atacama Desert. The European Extremely Large Telescope is planned there, too. But arguably the most powerful is the Thirty Meter Telescope, for which ground has already been broken on Mauna Kea.

Canadian astronomers and engineers have been leaders on the project from the beginning, and Canada has already invested more than $30 million in design and development.

But the Harper government must now dedicate another $300 million for the real work, money that will be used to build critical parts of the observatory in Canada and to make us an official partner, securing access for Canadian scientists.

Last year’s federal budget passed over the project, sowing uncertainty.

Without that money, Canadian designs will be handed over to foreign engineers, the two rival projects will surge ahead and Canadian astronomers will watch from the sidelines for a generation or longer as scientists with access to premier facilities scoop up all of the mind-expanding — and perhaps Nobel-worthy — science. Work like Jayawardhana’s risks being shut out.

The 2015 budget is Canada’s last chance.

“It’s at the point now where we’re ready to start building it. California has come up with their share of capital. So has China. So has Japan and India . . . . Everybody is kind of waiting for Canada,” says Paul Hickson, an astronomer at the University of British Columbia and co-chair for Canada on TMT’s science advisory committee.

“The train is leaving the station.”

At 4:30 p.m. the next day, Jayawardhana and Esteves grab their brown bag “night lunches” and climb into one of the four-wheel-drive SUVs parked outside.

Visitors to the tourist centre nearby are confronted with a photo collage of wrecked cars piloted by foolhardy astronomy enthusiasts who chanced the steep road to the summit and whose brakes gave out on the descent. The trip lasts 20 minutes and climbs 1,400 metres. The road is unpaved most of the way to provide traction; while temperatures at sea level average around 25 degrees, Mauna Kea endures occasional snow squalls.

The road ultimately flattens into an alien landscape: hummocks of dry red earth topped with shining silver domes and a view down over the cloud cover. At 4,207 metres, we are far above the treeline; winds can reach 160 kilometres an hour. Ancient shrines dot the slopes of Mauna Kea, but archeologists believe the summit itself was off-limits to all but the most powerful chiefs and priests.

Decades ago, astronomers determined the best “seeing” sites worldwide, places where light pollution and the blurring effects of the Earth’s atmosphere are diminished and where cloudy nights are rare. Mauna Kea ranked at the top, and ever since the summit has been nearly as important to astronomy as it is sacred to Hawaiian spiritual tradition.

As they wait for sunset, Dan Birchall, one of two permanent Subaru science staff responsible for the night running smoothly, gives the visitors a tour. In the centre of the building, girded in blue aluminum for the colour of the young stars in the cluster for which the telescope was named — the Pleiades or, in Japanese, Subaru — lies the observatory’s 8.3-metre primary mirror. It took three years to cast and four years to polish, resulting in a surface so smooth that the average bump is no bigger than 12 nanometres, one five-thousandth the thickness of a human hair.

The bigger the mirror, the more light collected from the skies. So telescope mirrors have grown in tandem with astronomers’ ambitions and engineers’ capabilities. Subaru is among the world’s best, the eight-metre to 10-metre class that also includes telescopes with names like Gemini, Keck and “VLT,” for Very Large Telescope.

Yet an observing run at any of these will be duller than at the eyepiece of an amateur instrument in Toronto. There is no eyepiece here, just two dozen computer screens flashing numbers and diagrams.

“Modern astronomy consists of long periods of boredom punctuated by brief periods of panic,” says Birchall.

Between 6 p.m., when Subaru’s dome opens, and 6 a.m., when it closes, the highlights of the night will be comparing night lunches, experimenting with nasal oxygen tubes and Skyping with Ernst de Mooij, Jayawardhana’s former post-doc and the principal investigator on the Subaru proposal. The starry night sky, while impressive, is clearer at the visitor’s centre, because the 40 per cent drop in oxygen at altitude affects human vision.

All of the night’s hard work is being done by an instrument called HDS, or High Dispersion Spectrograph.

Most people learned in grade school that light is actually a spectrum. When white light passes through a prism, it separates into the rainbow of wavelengths that we can see with the naked eye. There are additional wavelengths at either end of the spectrum that we can’t see.

Astronomers use that same principle to parse the properties of atmospheres on extra-solar planets or “exoplanets,” the worlds that orbit stars other than our own. When an exoplanet’s orbit brings it between its host star and us, the star’s light will travel through the planet’s atmosphere (if it has one). Gases in the atmosphere absorb some wavelengths more efficiently than others. If astronomers are able to collect enough of that host star’s light and separate it into its component wavelengths with a spectrograph, they can look for the telltale fingerprint left by each atmospheric gas.

Gases like oxygen and methane are considered stronger indicators of life or “biosignatures” because they are produced by plants or bacteria. Water is less suggestive but more vital.

“We are looking for water because almost more than any other substance, the search for life in the universe is intimately tied for the search for water,” says Jayawardhana.

Astronomers have found water in the atmosphere of Jupiter- and Neptune-sized planets, but Jayawardhana and his team would be the first to discover it on a Super Earth, an exoplanet two times the size of Earth and a closer analogue to our own. Though 55 Cancri e is 1,700 C and likely uninhabitable, the search for life on other planets is one of careful increments, not eurekas.

As the sun rises and the team begins the bleary drive back to the dormitory, the car passes the turnoff for a trail that peters out on the horizon: the future site of the Thirty Meter Telescope.

As Jayawardhana warned, characterizing exoplanet atmospheres with the current generation of telescopes is an ambitious task, and perhaps an impossible one.

“What we are struggling with is trying to tease out an incredibly faint signal against the immense brightness of the star. The more light you can collect per second, the higher our chances of having sufficient signal to noise,” Jayawardhana explains back in Toronto. Esteves returned for a second observing night in January to gather more data. It will still take weeks or months of number crunching to see anything.

With the vastly increased light-collecting power of TMT, the science would be much more likely to succeed. Whether Jayawardhana, Esteves or any Canadian astronomer will have access to those facilities is a decision currently in the hands of the Harper government.

Canada has had an outsized reputation in astronomy and astrophysics for nearly a century.

In 1918, an ambitious farmer’s son turned scientist named John Plaskett built a 1.8-metre telescope at the Dominion Astrophysical Observatory in Victoria. It was the second-largest telescope in the world at the time — a bold leap forward for such a young country.

“Canada has never looked back,” says Gregory Fahlman, general manager of the National Research Council’s Herzberg Astronomy and Astrophysics portfolio, the facility that succeeded the Dominion observatory. “We have been in the front rank of astronomy for a very long period of time.”

In 2012, at the behest of the federal government, the Canadian Council of Academies studied a wide variety of indicators and identified six research fields in which Canada excels and nine subfields in which Canada leads the world in scientific impact. Astronomy ranked in both.

Canadian astronomers racked up important discoveries throughout the 20th century and the 3.6-metre Canada-France-Hawaii Telescope on Mauna Kea, inaugurated in 1979, helped cement the country’s reputation.

Then, in the ’90s, Keck happened. Non-Californian astronomers still talk about the twin Keck telescopes, the first of the 10-metre generation, with a twinge of lingering trauma.

Until then, almost all major optical telescopes had been built with a single primary mirror. The Keck telescopes, under the direction of scientists at the California Institute of Technology (Caltech) and the University of California (UC), tossed out the single-mirror design and replaced it with a honeycomb of 36 smaller mirrored segments.

“There were a lot of people saying these telescopes weren’t going to work,” says Ray Carlberg, an astronomer at the University of Toronto.

They were very wrong.

In May 1993, when Keck I began scanning the skies, researchers at those two universities began publishing startling discovery after startling discovery. To name just one: Keck helped determine that the expansion of the universe is accelerating, a finding that led to the Nobel Prize.

The impact of the telescopes was so significant that astronomers minted a verb: to be “kecked” was to see your best faculty and students leave for California, the only schools with access to the observatories.

“It drained a lot of the best people away,” says Carlberg. It was five years before anyone finished a competing eight- to 10-metre telescope.

Lots of important science can be done with old telescopes. Even Plaskett’s 1.8-metre telescope is still in use. Canada has a stake in the two 8.1-metre Gemini telescopes — one of a rash of Keck-catchups that came online in the late 1990s — but in 2000 astronomers in Canada began looking ahead.

Carlberg and colleagues proposed a 20-metre telescope that would replace the Canada-France-Hawaii Telescope. Soon, however, they learned of two other planned 30-metre telescopes, including one by the California universities.

“Reason prevailed,” says Carlberg. The groups joined forces and, in 2003, Caltech, UC and a coalition of Canadian universities became founding partners in the Thirty Meter Telescope.

They have spent the subsequent decade figuring out how to build and fund it.

“The thing about big science projects is they haven’t been done before, so you’re not quite sure how to do it,” says Carlberg. The building permit alone, slowed by Hawaiian concerns over Mauna Kea’s environment and sanctity, took six years. “It’s probably easier to build a pipeline.”

There were a couple of obvious places in Canada to turn for two critical components of the new observatory.

Anyone who has flown through Hogwarts on the Harry Potter ride at Universal’s theme park in Orlando, Fla., is acquainted with the work of Dynamic Structures Ltd. Theme park rides are an outgrowth of the company’s global business housing telescopes.

Dynamic Structures designed and built the Canada-France-Hawaii Telescope’s enclosure in the 1970s and went on to win contracts for the enclosures at a star-studded list of international observatories, including Keck, Gemini, Subaru and the new Atacama Cosmology Telescope in Chile.

“Every one is different — different sites, different challenges,” says the company’s longtime president, David Halliday, who was called a “model of Canadian ingenuity” when he was admitted into the Order of Canada in 2011.

“TMT is the biggest challenge of all.”

After seven years of work, Dynamic Structures developed an enclosure for TMT that is almost the same size as Keck’s, despite the new mirror being three times as wide — 492 honeycomb segments versus 36. The plans feature a huge, eye-like opening that rotates on bearings rather than relying on the usual series of shutters, a solution that protects the telescope from wind, reducing ground-level disturbances.

The second Canadian shop scientists could turn to was NRC-Herzberg in Victoria.

“The thing that really makes TMT an extremely compelling observatory is the image quality,” says Scott Roberts, TMT systems engineering group leader, and formerly of Herzberg.

With a tool known as adaptive optics, astronomers are able to cancel out the blurring effects of Earth’s turbulent atmosphere. Engineers at Herzberg built the adaptive optics systems for the Canada-France-Hawaii Telescope and Gemini, and are considered leaders in the field. The instrument Herzberg is designing now, known as NFIRAOS and pronounced “nefarious” — “it’s a devilishly clever instrument,” says Fahlman — will be one of three ready for TMT’s first night of science.

A 30-metre mirror collects nine times as much light as a 10-metre mirror, but adaptive optics concentrates the light in one-ninth the space, allowing TMT’s scientists to boast that the new technology represents an 81-fold gain over Keck.

“It’s not any stretch to say that if the adaptive optics don’t work the telescope won’t work. There is a lot of confidence in Canada being able to do this,” says Roberts.

Biology has the Human Genome Project. Physics has its particle accelerators. But astronomy has never had a billion-dollar Big Science project until now: the three next-generation optical telescopes, along with the Atacama Large Millimeter Array and the James Webb Space Telescope, are the first.

Canada has contributed more than $30 million to develop TMT, but the structure is now ready to be built. The Canadian TMT team has asked the government for $300 million to do so. Half is for fabricating the enclosure and erecting it on site and one-sixth is for NFIRAOS and related adaptive optics equipment. The full amount will make Canada a 19 per cent partner in the finished observatory, which works out to around 60 observing nights a year.

“It’s hard to overstate how big an impact it will have for us to have Canadian access to TMT,” says Jayawardhana. “When you’re trying to play on the frontiers of human knowledge, which is what we are doing as we try to find and characterize these alien worlds, the game is all about having the best instruments and telescopes.”

The “science case” for TMT stretches way beyond habitable exoplanets: from probing the properties of dark matter to examining galaxies from the earliest years of the universe and supermassive black holes, next-generation telescopes will hit on nearly every important question in astrophysics, astrobiology, cosmology and more.

For the federal government to pass on the telescope “would be very unfortunate, almost a tragedy.”

For Jayawardhana, a dean, attracting and retaining talent also looms large. “There is so much value in terms of recruiting — getting the best people to work at our universities . . . If they had to go elsewhere to get access to facilities like TMT, the country would lose them.”

Jayawardhana himself is a testament to the power of Canada’s current reputation: the Sri Lankan native with degrees from Yale and Harvard left a job in the U.S. to move to U of T and then York.

Also at risk is the economic stimulus the project represents. “The enclosure is what the government has been talking about: it’s jobs. It’s guys that cut and weld and bolt and do all that big engineering stuff,” says Carlberg.

For Halliday, the prospect of passing over the plans for the enclosure is painful: “That’s ours.”

The TMT could be another Canadarm, a visible manifestation of Canada’s excellence. It could also be another Avro Arrow, the cancelled fighter jet still taught in high schools as a national embarrassment.

When the government passed on funding the telescope last year, those closest to the project were not surprised or particularly upset: it had become clear by the previous fall that in a deficit budget there would be no new money. This week, an Industry Canada spokesperson said that the government has invited the scientists to apply for money under the new Canada First Research Excellence Fund.

The other TMT partners — which now include Japan, India and China — agreed to begin construction on a reduced schedule in order to give Canada another shot; for the country to pull out now would throw the expected finish date of 2022 into doubt.

There is a race underway, after all. The researchers are diplomatic, saying all three telescopes are complementary and the competition is “collegial.” But a race is a race.

“Astronomers use the analogy of skimming the cream off the top,” says Roberts. “There are some key science cases where people know that if they had the Thirty Meter Telescope, in a matter of a few nights, they could do science that is just not possible right now.

“The first large telescope on the sky that has those adaptive optics capabilities will do that science, and that’s kind of Nobel Prize science.”

Every Canadian involved with the TMT says they are optimistic that the government understands the impact of this project; Carlberg, who is arguably the most familiar with the bureaucratic process, seems the most assured.

But he makes the case for the telescope plainly.

“There is no point in doing third-rate astronomy. You want to do first-rate astronomy or not bother,” he says. “We all love hockey, but need to support other areas of excellence.”

Toronto Star

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