Arecibo Observatory, the world's largest single-dish active radar telescope in the world, may be shut down or even destroyed due to funding concerns.

305-meter dish at the Arecibo Observatory, the world's largest radio telescope .NAIC
The 305-meter dish at the Arecibo Observatory, the world's largest single-dish active radar telescope.

Arecibo Observatory, which at at 1,000 feet across is the world’s largest single-dish active radar telescope, may be shut down or destroyed due to flat budgets at the National Science Foundation (NSF). The 53-year-old radio and radar telescope, located in Puerto Rico has been an invaluable scientific instrument for Nobel prize-winning radio astronomy, critical radar characterization of potentially-hazardous asteroids, and upper atmospheric studies.

The NSF released a “Dear Colleague” letter at the end of September 2016 that requested proposals for future operation of the observatory “under conditions of a substantially reduced funding commitment from NSF.”  The agency’s current budget for running Arecibo Observatory is approximately $8 million per year. Combined with about $4 million that NASA provides annually to operate the facility's planetary radar system, Arecibo’s total budget is approximately $12 million per year.


Arecibo Observatory isn’t the only facility supported by the NSF. In addition to providing research grants for individuals at universities and research institutes around the United States, the NSF provides funding to the National Solar Observatory, Green Bank Observatory in West Virginia, Very Large Array in New Mexico, and others. Additionally, the NSF has made financial commitments to build new telescopes, such as the Large Synoptic Survey Telescope currently under construction in Chile.

With NSF’s astronomy budget projected to stay flat for the foreseeable future, the organization has to prioritize the funds for all of its observatories and facilities, as it can't afford both to maintain prior commitments and to pay for new telescopes as their budgets increase with time.

Last March, NSF’s Astronomy and Astrophysics Advisory Committee recommended that the NSF’s financial focus be on funding new observatories, rather than supporting existing facilities such as Arecibo, and that the organization should disentangle itself from funding commitments “as fast as is practical.”

The Price of Shutting Down

As part of the process to decide Arecibo’s fate, the NSF commissioned an environmental-impact study to determine the consequences of deconstructing the observatory. The radio telescope’s most striking feature is a 900-ton platform suspended from 500-foot-long cables held up by three towers that sit at the edge of a giant sinkhole surrounded by limestone karst hills. Dismantling such a structure would not be easy — or cheap.

This isn’t the first time Arecibo has faced funding uncertainties. An NSF senior review in 2006 also recommended closing the observatory, but the astronomy and planetary-science communities rallied their support for the telescope. NASA stepped in, offering external funding for a planetary radar system to characterize asteroids. At the time, the senior review estimated that it might cost $300 million to return the site to its natural state.

Our best look at asteroid 101955 Bennu thus far, via radio data from Arecibo. The image at left shows radar reflectivity, with the radar illumination shining from the top. At right is a reconstruction of Bennu's shape using those data.
NASA / Arecibo


In NSF’s latest environmental impact statement, officials write that, rather than continue to fund Arecibo at current levels, they prefer to shut off the planetary radar system, purportedly because of its perceived minimal benefit to public safety. The statement dismisses planetary defense, stating (incorrectly) “there currently is no tested technology available that could address the threat of [an asteroid] that presents a near-term threat of striking the Earth.”

This section does not acknowledge Arecibo’s role in predicting and ruling out potential Earth impacts decades to centuries in the future (such as from 99942 Apophis, 101955 Bennu, and 1950 DA). Moreover, Arecibo’s radar follow-up of survey discoveries has a 10% chance of identifying an asteroid likely to strike Earth  within the next couple of centuries that would be worth deflecting. The draft also doesn’t acknowledge the harm done by small impact events, such as the almost 1,500 people injured by the Chelyabinsk bolide in 2013.

Further, NSF’s statement doesn’t mention either of the proposed asteroid deflection demonstration missions: ESA's AIDA (kinetic impactor) and NASA's ARM (gravity tractor). The mission teams and the Arecibo staff have issued public statements emphasizing that Arecibo’s radar observations should continue through the end of 2025, as they will be critical to verifying that both missions have deflected asteroids as intended.

The public can comment on the draft environmental impact statement regarding the future of Arecibo Observatory until December 12, 2016.

The NSF plans to publish the final environmental impact study about Arecibo by May 2017. Should the agency ultimately decide not only to divest from Arecibo but also to deconstruct the facility, such a plan could be put into action soon after June 2017. Whether Arecibo Observatory continues operating after the NSF’s ultimate decision about the telescope’s future remains uncertain, but it does not negate the critical scientific results Arecibo Observatory continues to produce.


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November 4, 2016 at 2:25 pm

Thank you for the update on the Arecibo Observatory.

Do you have any news on the status of the Green Bank Observatory (West Virginia)?

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Anthony Barreiro

November 4, 2016 at 3:16 pm

Here's the latest on Green Bank:

The National Science Foundation is soliciting public comments on different alternative plans for Green Bank -- continued NSF funding as a science facility; collaboration between NSF and other organizations; whether to focus on science, public education, and/or technology; mothballing the telescope; or "deconstructing" the facility and restoring the site to a natural condition.

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Anthony Barreiro

November 4, 2016 at 3:31 pm

I'm all in favor of new telescopes, but it bothers me that government agencies and universities always propose shutting down older facilities that are still doing good science in order to pay for the latest shiny new thing. The new facilities are always more expensive to build and operate than the old ones, so if this strategy succeeds we will have fewer and fewer, but bigger and bigger, telescopes. Only a small cadre of established researchers will have access to these behemoths, and proposals from younger researchers will have no chance of getting telescope time.

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GH Martin

November 4, 2016 at 7:20 pm

A somewhat political comment -- two candidates can spend hundreds of millions of dollars on political ads, and yet we may shut down an invaluable asset such as Arecibo for lack of $8 million? Where are our priorities? How about a "Go Fund Me" for Arecibo? I'd set it up myself if I knew how, but surely someone reading this knows the way.

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November 5, 2016 at 12:02 am

This is the result of a Congress in the thrall of military contractors. While there is always great clamor from one side of the aisle to increase military spending, these same legislators deliberately starve anything having to do with culture, society or science that doesn't directly lead to some new, wasteful weapon system.

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November 7, 2016 at 1:39 am

"Crowdfunding" could be a great way to go if the main funding is lost. It's literally "vote with your dollars." Maybe they could continue something/all/more with crowdfunding. Soliciting for dollars would then be the challenge, but so do most projects.

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November 9, 2016 at 9:06 am

like your comment or may be make some movie like contact 2 or ....... and donate the money to Arecibo, I sure watch the movie.

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November 5, 2016 at 1:06 pm

Exactly, Jim. My home town, Baltimore, was just visited by the Admiral Zumwalt, the navy's new, radar eluding destroyer....the most expensive destroyer ever built. Cost: $4 billion. Meanwhile, Baltimore is significantly increasing its charge for water to finance a make over of a rapidly (extremely!) deteriorating, 100 year old water distribution system. Meanwhile, the state is cutting it annual budget by $81 million because of a revenue shortfall. Obviously the defense secretary doubles as treasury secretary!

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November 5, 2016 at 4:37 pm

The iconic McMath-Pierce solar telescope on Kitt Peak, in operation since 1962, has also lost NSF funding. Its future is up in the air as well.

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November 6, 2016 at 7:47 pm

Sad news indeed... on top of the news of UK Comet discoverer Roy Panther dying the other day, we hear about THIS.
Another in a long list of great observatories, still doing excellent work, that are about be to axed. Can some rich benefactor (say, with a SETI affiliation), perhaps bank-roll it for another decade or so.
Mr Speilberg, Sir... are you reading this?
I wonder if Peter Jackson would be interested... he's a Kiwi.
Perhaps even Steve Balmer from Microsoft, Mr Zuckerman of Facebook... there are a few possibilities.

Yes, I know there is a slightly bigger version of the Arecibo Dish recently built in China, BUT.....

Graham Wolf at 46 South, NZ.

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