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

[Ron Baalke]

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.

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