Big Glass and the Age of New Astronomy The fight to put a monster
telescope on Mauna Kea is part of a bigger war looming among
astronomers.

By Dennis Hollier, Air & Space Magazine September 2016

The tallest island mountain in the world is Hawaii’s Mauna Kea,
where the thin atmosphere and absence of light pollution create
some of the best observing conditions for astronomers. At the summit,
13 telescopes sit along a ridge of formations that have built up
around volcanic vents. The oldest telescope on site, and still the
smallest, is the University of Hawaii’s 2.2-meter (7.2-foot) UH88,
built in 1968. Mauna Kea is best known as the home of the twin
10-meter Keck telescopes, which saw first light in the 1990s and
remain two of the largest optical and infrared telescopes in the
world. Collectively, this baker’s dozen of observatories has dominated
ground-based astronomy for four decades. But recently, Mauna Kea
has become embroiled in a dispute that could radically alter the
future of astronomy, and serve as a cautionary example of what we
might lose if it keeps going down this path.

In 2009, Mauna Kea was chosen as the site for the Thirty Meter
Telescope, a mega-observatory proposed by the California Institute
of Technology, the University of California, and national science
agencies in Japan, Canada, India, and China. Its massive mirror
will be made from 492 segments and have 81 times the sensitivity
of the Keck telescopes. Ed Stone, a Caltech physics professor and
the executive director of TMT (not to mention former director of
NASA’s Jet Propulsion Laboratory), explains why scientists are
pursuing a telescope more than three times the size of the biggest
one currently on Mauna Kea: “If you want to see the very first stars
in the universe,” he says, “you need a telescope of this class.”
Keck has been able to observe a galaxy that existed about 570 million
years after the Big Bang, but it just isn’t capable of observing
the most distant stars, the first ones, which formed about 400
million years after the creation of the universe.

“Another frontier that needs the collecting power of a new generation
of instruments is the study of exoplanets,” Stone says. “Our challenge
is developing the technology and capability to study those planets—for
instance, to determine whether microbial life might have evolved
on them.” These are the types of fundamental questions the TMT
should be able to address. And yet, the giant telescope may never
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This story is a selection from the November issue of Air & Space
magazine

In October 2014, as officials and construction crews headed to the
site for the ground-breaking ceremony, a group of native Hawaiian
protesters blocked their access to the summit and refused to move
until the project was stopped. Native Hawaiians consider Mauna Kea
a sacred site—many generations have returned to the mountain to
bury the piko, or umbilical cords, of their newborn children (piko
also means “mountain summit” in Hawaiian)—and have been vocal in
their opposition to building observatories there for years. Hawaii’s
governor, fearing violence might break out, negotiated a temporary
halt in the construction. Then, last December, the state’s supreme
court vacated the observatory’s building permit, sending the
application back to the land and resource agency for a new hearing.
Though the telescope’s managers still hope to build on Mauna Kea,
they also fear a long legal battle that they will eventually lose,
and have started to seriously consider sites in Baja California,
the Canary Islands, Chile, India, and China.

Some Hawaiians are also fighting the extension of the entire
observatory complex’s 65-year lease on the summit, which expires
on December 31, 2033. Doug Simons is the director of the 3.6-meter
Canada France Hawaii Telescope and former director of the Gemini
Observatory, which has twin eight-meter telescopes on Mauna Kea and
in Chile. He says that without assurances that the master lease
will be extended, the agencies that fund the observatories will be
reluctant to invest in improvements or new instrumentation. In fact,
some observatories had already begun to change operations in
preparation for the Thirty Meter. TMT’s Japanese partner operates
Mauna Kea’s eight-meter Subaru telescope, and had started winnowing
its instrumentation so that it operates exclusively as a wide-field
telescope in collaboration with the new arrival. “They haven’t gone
so far down the path that it’s irrecoverable,” Simons says. “But
they have taken the most steps of all the Mauna Kea observatories
in advance of TMT’s arrival.” If the giant telescope isn’t built,
Subaru will have to reconfigure again to remain a meaningful
contributor to astronomy. And if the native Hawaiians succeed, the
entire scientific complex will be dismantled, and the land returned
to the state.

The controversy surrounding the TMT and its impact on the other
Mauna Kea observatories seem like a local story, but the struggle
is also symbolic of a broader problem. Over the past few decades,
the field of astronomy has been dominated by efforts to build newer
and bigger telescopes. The TMT is projected to cost $1.4 billion,
and the other observatories being built in this wave (all three in
Chile) come with similar price tags. The Giant Magellan Telescope,
which will actually house seven 8.4-meter telescopes, will likely
exceed $1 billion. The staggeringly huge 39.3-meter European Extremely
Large Telescope, or E-ELT, is projected to cost $1.35 billion. And
the relatively dainty 8.4-meter Large Synoptic Survey Telescope
(LSST) will cost $650 million to construct, but the bill goes up
over $1 billion when it includes operation for the 10-year sky
survey the instrument is projected to start in 2020. “A billion
dollars is pretty much the entry fee into this particular game,”
says Shrinivas Kulkarni, Caltech’s director of optical observatories.
Palomar Observatory With only an 18-inch mirror, Palomar Observatory’s
first telescope made historic discoveries for nearly 60 years.
(Palomar/Caltech Archives)

Because Caltech is one of the primary partners of the Thirty Meter
project, part of Kulkarni’s job is to oversee that investment. But
even though he strongly supports building the observatory, he
believes the trend toward these massive and costly projects represents
a sea change in how astronomy is practiced. Increasingly, Kulkarni
says, the study of the universe has become the province of
physicists—especially particle physicists—and they look at the world
very differently than astronomers do.

“Astronomers used to be the phenomenologists of the universe,”
Kulkarni says. “Just as a plant biologist studies plants of various
sorts and a zoologist studies various sorts of animals, an astronomer
does the same thing for the universe. We go and look for stars, for
galaxies, for intergalactic media, and we catalog them. We see how
the energy formed; what’s the life-cycle of stars; what’s the end
product; what’s the ecosystem. You could almost regard astronomers,
like zoologists and biologists, primarily as explorers, as catalogers
and explainers. That’s what we do.”

But two things changed that, he says. The first was the discovery
of cosmic background radiation in the 1960s. This radiation,
essentially the first light in the universe, dates back to just a
few hundred thousand years after the Big Bang. In 1989, NASA launched
COBE, the Cosmic Background Explorer, which enabled astronomers to
begin seriously probing its nature. COBE and several subsequent
spacecraft, including Europe’s ongoing Planck mission, have mapped
the distribution of this radiation across the universe. “The discovery
of background radiation showed the real link between astronomy and
basic physics,” Kulkarni says. Even though the discovery was largely
driven by the techniques of astronomy, it fell to physicists to
explain the high-energy environment right after the Big Bang.
Suddenly the entire universe was a laboratory for particle physicists.

This blending of physics and astronomy was initially a boon to both
fields. Kulkarni points out that it was a theoretical physicist,
Alan Guth, who came up with the idea of cosmic inflation, one of
the central ideas of modern astronomy.

The second big change in astronomy was the discovery of dark energy.
In 1998, two groups of astrophysicists studying supernovas found
evidence that the universe wasn’t just expanding, but expanding at
an accelerating rate. This Nobel Prize-winning discovery led to the
postulation of a form of energy that would explain the outward
force. Dark energy is now believed to account for more than 68
percent of the energy and matter in the universe. (Dark matter makes
up 27 percent. Ordinary matter, the stuff you can see and detect,
makes up the rest: less than five percent of the universe.) Hawaiian
protesters Last year, native Hawaiian protesters, who believe Mauna
Kea is sacred, blocked construction vehicles from the new telescope
site. (Holly Johnson/Hawaii Herald Tribune via AP)

These discoveries advanced our knowledge of the universe tremendously.
But they also forced physicists and astronomers to learn how to
live together, says Kulkarni. “The culture of particle physics is
different,” he says. “As much as astronomers are phenomenologists—explorers
who want to see the breadth and diversity in the universe—physicists
are the exact opposite. They’re what we call reductionists. They
try to reduce the complexity of the observations of phenomena into
as few principles as possible.” The whole body of what we now call
mechanics derives from Newton’s second law of motion: Force equals
mass times acceleration. The predictive power of this kind of theorem
has made physics the king of sciences, Kulkarni says, and mathematics
the queen. Unlike astronomy, the basic impetus of physics isn’t to
discover something new; it’s to develop theories to explain known
phenomena, then create experiments to test those theories. Because
of the growing influence of physics, the discipline’s method is
steering the entire field of astronomy in that direction too.

Today, an enormous amount of money is being spent on these grand
experiments—many of which are similar. “The Europeans are launching
the space mission called Euclid, which, as the name implies, is
looking at the geometry of space,” says Kulkarni. “Not to be outdone,
in 2025, the U.S. is launching something called WFIRST, which will
also produce a geometry of the universe. And one of the main goals
of LSST is to measure the geometry of the universe. So there’s been
an enormous investment of money into these very large, high-profile,
almost singularly focused, fundamental experiments.”

Those observations are bound to teach us a lot, but as Kulkarni
sees it, the facilities required to do the experiments are of such
a scale that they limit the amount of other types of astronomy that
can be done. Lost in all this will be the serendipity that comes
from basic exploration.

Although other astronomers may disagree with Kulkarni about the
severity of the problem, his basic premise isn’t particularly
controversial. Especially coming from someone at Caltech, says Doug
Simons: “Look at the history of Palomar [Observatory] and Caltech,
which has dominated the field of astronomy like no other school.
Who discovered quasars, for example? That was substantially done
at Caltech and Palomar. Nobody even knew that such objects existed
in the universe…. We know now that black holes power quasars, but
when [Dutch astronomer Maartin] Schmidt identified the first quasar,
QC273, it was a completely unpredicted product of innovative observing
at Caltech. That’s what [Kulkarni] is talking about: finding things
you never knew or even imagined existed in the universe.”

But not everyone agrees with the notion that big physics-based
projects remove the chance for the serendipity that Kulkarni yearns
for. Ed Stone refutes that idea by pointing to the first detection
of gravitational waves at the Laser Interferometer Gravitational-Wave
Observatory, or LIGO. “I think that many astronomers now believe—once
one was detected for the first time, and the merging black holes
that caused it were determined to be much more massive than the
models suggested. That means we’ve learned something else about
nature besides just confirming Einstein’s theory of gravity. So in
many cases, an experiment starts out answering a physics question,
but then begins to answer questions having to do with astronomy and
astrophysics.” This is a LSST, a Thirty Meter Telescope with an
8.4-meter mirror. (LSST)

Even if you make the case that massive, narrowly focused observatories
like LIGO and TMT contribute to basic exploration, building them
still affects the rest of the field. The budgetary burden will fall
on the existing stable of smaller, older telescopes. Certainly
that’s the case on Mauna Kea, where part of the bargain to build
Thirty Meter included shutting down some of the older facilities.
To free up operational funds for new, larger facilities, the 2010
Astronomy and Astrophysics Decadal Survey recommended closing 84
older ones.

This, of course, seems like a perfectly sensible attempt to prioritize
projects in the face of limited resources. “Sometimes there is no
other way than to build a large instrument,” says Stone. “You just
have to very carefully choose which ones you decide to do next.
That’s why we have the Decadal Surveys, which the National Academy
of Sciences does to advise [the National Science Foundation] and
NASA.”

The decision to shut down smaller, older facilities may make sense
for budgets, but not necessarily for science. Rene Walterbos, who
chairs the board that oversees the Sloan Digital Sky Survey, points
out that unlike the big facilities that do particle physics research,
telescopes don’t become obsolete as they age. After the Large Hadron
Collider was built at CERN in Geneva, Switzerland, Fermi lab’s
Tevatron particle accelerator in Illinois was shut down because no
new research could be done at its lower energy levels. That’s simply
not the case for telescopes, Walterbos says. “In astronomy, any
telescope can keep observing. People still find useful things to
do, even with very small telescopes.”

If you’ve ever used a camera, you know that the more you zoom, the
narrower your field of vision becomes. The small telescopes of the
world may not see as far as their modern 10-meter siblings, but
they see wider. That makes the older generation of telescopes better
suited for broad surveys of the sky. Walterbos points out that the
Sloan survey, which for the past 15 years has operated two 2.5-meter
telescopes in New Mexico, has been one of the most productive
astronomy programs in the world. The Sloan survey has been
systematically creating three-dimensional maps of a large portion
of the universe, data that’s made public and used for research at
other facilities. Indeed, one of the main functions of smaller
telescopes is to find new things for the TMTs and Kecks of the world
to take a closer look at. At Mauna Kea this collaboration is
practically a matter of walking a new finding across the street.
“That’s exactly right,” says Gary Davis, former director of the
3.8-meter United Kingdom Infrared Telescope. “A lot of the discoveries
at UKIRT were followed up on Gemini’s larger telescope.”

Another cost of shutting down older observatories is more
straightforward: There will be fewer facilities where astronomers
can do research. Many astronomy students and faculty are at
universities that have no observatory; to conduct their research,
they compete for time elsewhere. But many of these new, large
facilities tend to be owned by groups of private universities, which
give first dibs to their own scientists.

“People may look at TMT and say, ‘Well, that’s great, but we’ll
never get in there,’ ” says Walterbos. “That’s a potential source
for real tension. Early in the next decade, the NSF will have to
figure out if they can afford to make an investment and be a partner
in that and, in return, provide access to the community. Or will
they not be a player at all? The pressure on their budget is severe,
and they have a very difficult job—as does the community as a
whole—figuring out what the balance will be.” A rendering of the
TMT (TMT International Observatory)

Another benefit of smaller telescopes is the flexibility for
astronomers to be creative, says Davis, who left Mauna Kea to work
on the ambitious Square Kilometre Array radio telescope being
designed for locations in Australia and South Africa. “That’s where
the real innovation happens, because it’s cheaper to do that
innovation on small telescopes. If I want to try some weird observing
mode, it’s easier to do that on a telescope that costs $1.2 million
a year to operate than one that costs tens of millions.”

Nowhere is the impact of the innovation at the smaller telescopes
more obvious than on Mauna Kea. Whenever the issue of old versus
new comes up, Doug Simons likes to pull out a list of observatories
worldwide that had the biggest scientific impact in 2015. It’s a
metric one of his colleagues calculated by taking the number of
publications that come out of a facility—a measure of productivity—and
multiplying that by the number of citations those publications
receive—a measure of influence. The twin Keck telescopes top the
list, but the next two are its sub-four-meter Mauna Kea neighbors:
CFHT and UKIRT, both of which have been operating for nearly 40
years.

That success, Simons says, is largely the result of a willingness
to take risks, particularly on instrumentation. In 1996, CFHT was
the first telescope to regularly support observations with adaptive
optics, the use of a high-speed, deformable mirror to cancel out
the effects of atmospheric turbulence in real time to get sharper
images. “My first job after graduating from the University of Hawaii
was as a resident astronomer at CFHT,” says Simons, “and I remember
the ferocity of the debates back then at this ‘black magic’
technology…. It wasn’t an easy decision, but we decided to go ahead
and pursue it at CFHT, and we were the first out of the starting
blocks. It was a spectacular success.” No major telescope today is
built without adaptive optics.

More recently, CFHT invested in the SITELLE, an instrument successfully
tested last year that analyzes the spectra of every object in its
view simultaneously. “SITELLE can measure the spectra of complex
fields in a couple of hours, which would take conventional slit
spectrometers many nights to complete,” says Simons. This is one
of a handful of novel instruments at CFHT, keeping it on the cutting
edge.  Flame Nebula Even small telescopes can probe nearby objects
like the Flame Nebula, searching for unexplained phenomena. Will
giant telescopes snuff out those searches? (David Thompson/Caltech)

Another key innovation at the older, smaller telescopes has been
automation. At Caltech’s Palomar Observatory, Kulkarni built an
enormously productive research program by automating two instruments,
the 1.2-meter and 1.5-meter telescopes. The wide-field survey,
called the Palomar Transient Factory, has cataloged millions of
supernovas and other short-lived features of the night sky. That
was only possible, Kulkarni says, because of automation, which
speeds up the process and frees astronomers from the mundane tasks
of their research. He’s reopening the survey again next year as the
Zwicky Transient Factory, using the same telescopes equipped with
updated cameras.

In fact, as older telescopes endure deeper resource cuts, the only
thing that will save some of them, says Davis, is embracing automation.
In 2010, he automated UKIRT so that the whole operation could be
run from the headquarters in Hilo, at the base of Mauna Kea. “After
making the changes, our operating budget went down to $1.2 million
a year,” says Davis. “On larger-aperture telescopes, it’s typically
tens of millions.”

Yet, all these advantages may not be enough to save the nation’s
older, smaller telescopes. Says Kulkarni, “Either you’re doing
astro-particle physics—some big experiment that costs a lot of
money—or you’re going to build a big telescope, like TMT, that also
costs lots of money. This completely squeezes the people who use
moderately sized telescopes, people that I call traditional
astronomers.”

So while the Thirty Meter Telescope’s location awaits judgment—even
if it isn’t Mauna Kea, the observatory will be built somewhere—a
generation of explorers ponder more existential questions about
their field. If the bright lights shining on Big Glass cast too
much shadow on the stable of workhorse observatories, will the
discoveries of astronomy fade into the darkness with them?

Dennis Hollier is a science writer and incrementalist, trying to
make sense of the world one story at a time.