[meteorite-list] Saving Arecibo: Observatory's Radar and Unique Precision Make It A Vital Resource

From: Ron Baalke <baalke_at_meteoritecentral.com>
Date: Thu, 18 Jan 2007 10:58:19 -0800 (PST)
Message-ID: <200701181858.KAA13500_at_zagami.jpl.nasa.gov>

http://www.news.cornell.edu/stories/Jan07/brown.arecibo.html

Chronicle Online

Saving Arecibo: Observatory's radar and unique precision make it a
vital resource, argues NAIC director

Jan. 18, 2007

By Lauren Gold
LG34 at cornell.edu

On Nov. 3 the Senior Review, an advisory panel to the National
Science Foundation (NSF) Division of Astronomical Sciences, issued
recommendations for the future of the Arecibo Observatory, which
Cornell manages for the agency through the National Astronomy and
Ionosphere Center (NAIC). Among the recommendations was a $2 million
budget cut over the next three years, and advice that the NAIC find
outside partners to cover half of Arecibo's total operating costs by
2011 or risk closure.

Reactions from Cornell and Arecibo astronomers have run from deeply
concerned to guardedly optimistic. Many acknowledge the competing
need to fund promising new facilities. But above all is strong
agreement about Arecibo's unique strengths, its decades-long lifespan
and the importance of keeping it running well into the future.

Robert Brown, NAIC director and adjunct professor of astronomy at
Cornell, discussed the report's impact on the observatory in a recent
interview.



How serious is the threat of closure?

My concern is that people will read the recommendation and expect
that the observatory will close. It would be extremely serious if
good people begin to leave the observatory for that reason. But
personally I'm very optimistic that the future will be actually quite
bright for the observatory.

We have looked for external funding and have been successful for some
specific programs. But there aren't foreign countries or institutions
that say, boy, I'd sure like to cut the grass at the observatory or
to pay the electrical bill. That said, it's to the advantage of the
U.S. astronomy community for support to continue, and everyone
understands that. Yes, the Senior Review had recommendations that are
contrary to that point of view -- but the Senior Review is not the
only forum in which these subjects are discussed. We believe that we
can convince the next decadal survey [2008-2010] of the value of the
observatory.



What are the most compelling reasons for saving the observatory?

The technology of the instruments used for astronomy has improved
dramatically in recent years. The ability to discover objects in the
sky has improved -- not just by a little bit, by a huge amount. So
that means that astronomy has had a renaissance. It's basically
started over again.

The thrust of all modern observatories is surveys. In our case, we're
surveying the sky looking for pulsars; for hydrogen in galaxies near
but not in the Milky Way; and a third program looks to study hydrogen
in the Milky Way. All in much greater detail than it has in the past.



So what happens now?

It's going to be a year filled with adventure. Institutionally, it's
not all bad to say okay, our funding is going to decrease -- let's
focus on the most important science we can do; let's do that well,
and then we'll grow from there. It's not an unreasonable thing to do,
and certainly we and the rest of the astronomy community genuinely
want to see new research facilities be built. If you don't build new
things, the field gradually will atrophy. The senior review exercise
is one that we believe in, so we're prepared to put up with its
consequences -- as long as it means paring us back by 25 percent or
so, and then allowing us to grow from there. If the recommendations
go further than that -- that's not something that I would support as
being beneficial to U.S. science.



There is talk of future threats from near-Earth objects, such as
asteroids. Why is Arecibo's radar vital for tracking these?

Arecibo has the world's only high-power radar. And it's terrifically
good at studying the terrestrial planets in the solar system, the
satellites of Jupiter and Saturn, and, in particular, near-Earth
asteroids. Many people are quite concerned by the threat that such
asteroids pose. We can determine the motion of an asteroid to within
about a millimeter per second. That's astonishing precision -- orders
of magnitude better than you can do by any other technique. And if
you have that information you can reconstruct the orbit of the
asteroid, or you can project it into the future to determine whether
the asteroid is likely to hit the Earth. Arecibo is the only place in
the world where you can do that.



The observatory is also engaged in sky surveys. What do scientists
hope to learn from these?

Take pulsars: We know about 1,000 pulsars, and of that 1,000, most
rotate between 10 times a second and once a second. Pulsars are
neutron stars with the mass of the sun but a diameter of about 10 km.
They're the endpoint of the life of a star, formed when a supernova
explodes.

A few known pulsars -- less than 20 -- exist as members of a binary
system. And some of those -- only five or six -- spin nearly 1,000
times a second. These are hugely important tools for studying general
relativity [and for probing properties of matter under extreme
conditions]. If you double the number known, which is what we're
trying to do at Arecibo, maybe you have 10 or 12. And then maybe
you've got enough to answer these fundamental questions. But you have
to survey the sky to find them.



What do hydrogen gas surveys reveal about galaxy formation?

In the case of the Milky Way about 10 percent of the matter is gas
and 90 percent is stars. In elliptical galaxies there is no gas --
there are just old stars. But it's the exceptions you look at. [The
ALFALFA survey, for example, is a project searching for galaxies that
consist mainly of hydrogen and dark matter -- but not stars. These
galaxies could provide essential clues to how galaxies form.]

Meanwhile, while we're looking for the mass of gas, optical
telescopes are looking for the composition of stars. It's these
pieces of information in combination that are really valuable for
research.

-- 

Received on Thu 18 Jan 2007 01:58:19 PM PST