Download in my own words Astronomy at the Frontier Matt Mountain, Ph.D.

Astronomy at the Frontier
Matt Mountain, Ph.D.
Director, Space Telescope Science Institute
As Director of the Gemini Observatory, Charles Mattias (“Matt”)
Mountain led the design, construction, and operation of Gemini’s two
8-meter telescopes in Hawaii and Chile. Since 2005, he has served as
Director of the Space Telescope Science Institute (STScI) in Baltimore,
Maryland, where he is responsible for the science operations of the
Hubble Space Telescope. He is also the Telescope Scientist for NASA’s
James Webb Space Telescope, as well as a professor in the Johns Hopkins
University Department of Physics and Astronomy.
Unique observations
At school, I became interested in
physics because it allowed me to work
in a lab and build things and see how
they worked. I could try to understand
how the universe worked and how
rockets worked. I got my degree in
physics at Imperial College in London.
Afterward, I considered becoming a
particle physicist, but then I was given
the opportunity to see a telescope
operating in the Canary Islands.
In those days—this was the 1980s—
astronomy was still a science that allowed an individual to
make unique observations. It was small science, and that
appealed to me. I went on to get my Ph.D. in observational
astrophysics.
Impossible discoveries
A lot has changed since then. Today, the average ground
telescope weighs 300 tons. It takes hundreds of people just
to build and operate. Astronomy has become a multidisciplinary science that requires not only physicists and
astrophysicists, but also optical scientists, cryogenicists,
engineers, and computer scientists. Astronomy, at the frontier, has become a big science where you need large teams
of people working together.
Astronomers still speak romantically of how it used to
be so nice to be alone, off on the summit, looking out at
the stars, but that’s no longer how we do it. Nobody “looks
through” the Hubble: you upload commands and the Hubble downloads data, which is then processed and sent out
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to the observer on the Internet. This separation between
astronomer and machine represents a dramatic change, but
this huge base of talent and these amazing machines are
allowing us to make discoveries we thought were impossible two decades ago.
A scientific renaissance
When I got into the field, the only planets we knew were in
our own solar system. Black holes were figments of a theorist’s imagination. Now we’ve identified over 3,000 planets.
We know that every star in our galaxy has at least one
planet and that there are approximately 100 billion planets
in our galaxy. Black holes are in the center of every galaxy.
We have dark energy and dark matter. We know the age of
the universe, and all this has happened in the last 20 years.
It’s like a renaissance of science.
It’s also been somewhat humbling, though. We discovered that we understand only four percent of the universe.
Dark matter and dark energy dominate the other 96
percent, and we haven’t a clue what they are. But those
very facts, and the fact that we now know there are planets
around every star and that we’re on the verge of measuring
what might be on those planets—you couldn’t have imagined that 20 years ago.
There are two big factors that have contributed to these
advances. One is the sheer power of the telescopes and
technology. Then there’s the explosion of data and the
inter-comparison of data across different wavebands. It’s
now quite normal for scientists to take data from the Hubble,
the infrared Spitzer telescope, and ground-based telescopes, and combine them into data sets.
Data-driven discoveries
Twenty years ago, astronomers agreed amongst themselves, internationally, on a standard format for all their
data irrespective of which telescope it came from or what
waveband they use. This has allowed us to build amazing
archives of data. Today, half the refereed papers from
Hubble—which is a measure of scientific output—come
from the data in our archives, not from the telescope. By
applying new computing techniques to old Hubble data,
we’re discovering planets that had been hidden in the data.
When I started, we had radio astronomers, infrared
astronomers, and optical astronomers. Today we have specialists in exoplanets, galaxies, or black holes. They comb
Sept/Oct 2014
NASA, ESA, H. Teplitz and M. Rafelski (IPAC/Caltech), A. Koekemoer (STScI), R.
Windhorst (Arizona State University), and Z. Levay (STScI)
in my own words
Hubble Ultra Deep Field 2014
roughly 300 miles an hour. To get it into orbit, it has to fly at
17,000 miles an hour. You need at least 1,000 times more
energy than a 747 has to get the shuttle into orbit, and that’s
really hard. Even though rocketry’s been around since World
War II, it’s still very hard. That also means it’s very expensive.
Now we have NASA-funded private players like SpaceX.
They’re just launching cargo and they’re still finding it really
hard to launch into space. But because private companies
can innovate and be flexible, they have the ability to cut the
cost to orbit—and maybe even cut the cost to deep space.
through data from the various telescopes looking for the phenomena they’re interested in. They use the multi-wavelength
bands and the archives, and they apply for telescope time
so they can contribute new observations to the archive. This
generation is completely at ease using big data to cross-compare, and they’re making a lot of discoveries.
When Adam Riess and his collaborators discovered dark
energy, they did so using a network of telescopes all over the
planet and off the planet. They used small telescopes, then
followed up with ground-based telescopes, and then used the
Hubble Space Telescope, and they cross-compared the data.
It couldn’t have been done without the interconnection of all
these data sets.
No looking back
The Space Telescope Science Institute is a very exciting
place to be. Every day, we’re deciding what the Hubble is
going to do. We’re getting to see what the new data looks
like and what discoveries our community is going to make.
We’re also preparing for the James Webb Space Telescope.
With the Webb we will, for the first time, be able to detect the
presence of liquid water on planets in just-right regions—the
so-called Goldilocks zone. Which immediately leads to the
question, Is there life out there?
Knowing that there is life on another planet would change
everything, because once we’ve discovered that, there’s
no looking back. Discovering life on another planet would
change our whole perspective as a species.
Astronomical challenges
But getting a seven-ton telescope like the Webb into space
is no easy matter. If you’ve watched Star Trek or Star Wars, it
looks easy to get out into space. It isn’t. Consider the Space
Shuttle, which was about the size of a 747. A 747 flies at
www.cty.jhu.edu/imagine
An expensive endeavor
Not only is it hard to get anything into space, but once it’s
there, it’s in a vacuum. We’ve got to build equipment that will
work in a very cold, radiation-filled vacuum. We’ve had to
carry all that mass into orbit, which is really expensive, and
most of the time, if we make a mistake, we can’t fix it.
The Hubble is unique. It was designed so that astronauts
could fix it. At the time, we had the shuttle system to take
astronauts up to fix it, but we no longer have that capability.
The Webb will be tested for two years to ensure there are
no mistakes. Then we’ll launch it on an Ariane 5 rocket out
beyond the Moon, about a million miles from here, where it
will be completely inaccessible to humankind. It has to work
reliably for at least a decade. That means a lot of testing,
thought, and engineering, which is extraordinarily expensive.
Managing big science
This is not a field for the faint-hearted. You have to be very
patient to accumulate the good will, consensus, and partnerships to get the resources you need for something like
the Webb, which will cost $8 billion to launch. You need very
large multinational collaborations and agencies, like NASA,
and you have to be willing to work in the kind of bureaucracy
big organizations have.
On the other hand, the rewards are enormous. The young
people who work here get to help decide what the Hubble
does or what the Webb will do. They’re brimming over with
excitement at the opportunity to control where the U.S.’s
premier telescopes look and to be the first to see the data
that comes down.
We’ve been working on new technologies in order to
produce a second-generation Webb 10 or 15 years from now
that could actually discover life on other planets. Yours may
be the generation that makes that discovery. It may be your
telescope that we build. n
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