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Comment by shiftpgdn | Hacker News Reader

What would the cost to rebuild be? Could it be crowd funded?

It's frustrating that isn't addressed in the article.

Does Arecibo do more than other comparable telescopes? Or will science and humanity go on? Is it worth the billion, or $200m, or whatever, to rebuild in the name of science?

Pretty clearly not. It's natural advantage has faded over time as tech progressed.

It's value would mainly be to show that we can afford to do some luxury science and local science, and be a focal point for Puerto Rico, which isn't necessarily bad.

If PR had representation in Congress, Arecibo rebuild would be an easy pork barrel project.

We have no other filled aperture radiotelescope of comparable area, with transmit capability. Filled aperture matters.

The only comparable telescope is the Chinese FAST radiotelescope, which is somewhat larger in diameter but without all the capabilities (and, you know. Being in China.).

> Filled aperture matters.

Could say the exact opposite... sparse synthetic apertures are more cost-efficient.

Totally depends on what you’re trying to do. Arecibo was used in transmit mode, too, for studying asteroids, etc. and the “thinned array curse” hits you hard if you don’t have a filled array for transmission as most of your energy ends up in sidelobes, not the central beam.

Plus, sparse array only works well for high contrast, high brightness sources. And it has a bunch of artifacts that can get in the way of interpretation of the data. Plus just pure filled area matters a lot.

It can transmit and it has a larger surface area (collecting area) than other telescopes.

Didymos has been in the news recently... https://en.wikipedia.org/wiki/65803_Didymos#/media/File:Didy...

Note the "Arecibo" in the file name.

> Fourteen sequential Arecibo radar images of the near-Earth asteroid (65803) Didymos and its moonlet, taken on 23, 24 and 26 November 2003. NASA’s planetary radar capabilities enable scientists to resolve shape, concavities, and possible large boulders on the surfaces of these small worlds. Photometric lightcurve data indicated that Didymos is a binary system, and radar imagery distinctly shows the secondary body.

That was done with radio pulses sent from Arecibo.

Science will go on, but we've lost a tool. The area of the dish remains unmatched.

https://space.stackexchange.com/questions/48666/arecibo-adva...

A similar, larger telescope[0] was put into service in China in 2016. There are a few things Arecibo could do that it can't (receiving frequencies above 3 GHz, transmitting), but in other areas it's better. So on the whole I can see how the need isn't that strong right now.

[0] https://en.wikipedia.org/wiki/Five-hundred-meter_Aperture_Sp...

Sell/auction off pieces from the original telescope and use that to help fund the replacement?

Or somehow convince Elon to buy it…

https://news.ycombinator.com/item?id=33232914

Some quick googling reveals that it cost 9.3 million in 1963, so inflation adjusted that would be about 100 million today. Not completely out of the realm of crowdfunding, but it would probably quicker to send a tweet to Elon Musk or Jeff Bezos and offer them to name it the "Jeff Bezos Arecibo Telescope" or somesuch if they fund the reconstruction by themselves.

Show Elon the 1974 Arecibo message and explain that it’s like an interstellar tweet, and for a mere $100 million he’ll be able to send those himself.

Honestly sounds like a bargain compared to his recent tweet spending habits.

> Show Elon the 1974 Arecibo message and explain that it’s like an interstellar tweet, and for a mere $100 million he’ll be able to send those himself.

Or just show him Goldeneye. I feel he'd be more likely to do it for the meme.

The cost disease for infrastructure has expanded dramatically faster than inflation and I really doubt you could do this for less than $2B today.

Unless you get a magic "no environmental review" exception (you won't).

PR doesn't have the powerful NIMBY culture that California does.

Folks there are less wealthy and more practical about the value of adding local economic investment.

A lot of construction costs are also related to the insurance, specially against liabilities, financial costs and other, non-enviromental costs. Even if you're building a more amicable jurisdiction, those costs cascade down from your upstream supply chain.

True overall, but it still only takes one Sierra Club to gum it up in court for years. It's not like the neighborhood can vote to override federal courts.

Chinese tax breaks, and no piss-breaks for the workers could help pay, too.

Maybe with an offer to be top of the list of who gets notified when the aliens are first detected ..

I think that more than the reconstruction there probably isn't any will to pay for operations or maintenance anymore (after all, this probably wouldn't have happened in the first place if maintenance was better). So even if any billionaires decided to foot the bill, the issue would remain that a long term commitment to supporting the facility is also needed, and while short term large expenditures are tolerable to most rich companies and individuals, the long term commitment with no clear end or outcome is probably the limiter.

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