Arecibo telescope won’t be rebuilt | Hacker News Reader

Arecibo telescope won’t be rebuilt

nature.com

252 pointspseudolus192 comments

Why rebuild it? While cutting-edge when it was originally built, my understanding is that computationally combined arrays of smaller dishes are today considered superior to what Arecibo was, for radio astronomy.

I’d be interested to hear from folks with expertise whether that is right or wrong.

It goes beyond being a state of the art tool. It is a part of our culture having this observatory.

As a child, I loved going there and its the earliest part of my childhood that I remember something motivating me to pursue science/math. Even in my later part of my life I was able to do some research with the observatory which kick started my current career.

The island already suffers from a lack of funding in education, thus I fear the youth might miss out on this sense of awe and curiosity I was lucky enough to have as a child.

Another issue is that we have our brightest minds leaving the island because there's no fulfilling or well paying work to be done. The lack of this observatory is another reason more people will leave.

Here's a white paper the people in the observatory wrote about a new dish. It contains reasoning, beyond my socio-cultural observations, for having a new one. http://www.naic.edu/NGAT/NGAT_WhitePaper_v2_01022021.pdf

Funding for local projects is competitive at the federal level from what I understand. If it doesn't serve a primary scientific purpose, then why would Puerto Rico be put at the front of the line?

i.e. there's 50 other states and D.C. competing to be the most attractive to big ticket project funding, which also deliver education, youth initiatives, high paying jobs, etc.

Because Puerto Rico is filled with American citizens who also deserve those things, and it's a vibrant island filled with scrappy, resilient people?

Sure, but the other 50 states are also filled with American citizens who deserve things, many of whom are scrappy and resilient. OTOH, the money being spent is also ultimately that of the American citizens', so the government should strive to accomplish the most it can for any given mission and budget.

In this case, the calculus may simply be that the mission can be more comprehensively and efficiently achieved via investments elsewhere that will similarly benefit Americans near those areas as a reinvestment would have benefitted in Puerto Rico.

The major difference, of course, is that those states have federal representatives with voting power to advocate for their needs and Puerto Rico does not.

The story of the death of Arecibo is a stain on the way the United States treats its colonial territories.

The state of the island's electrical infrastructure is a much larger stain than the loss of an aging radiotelescope. Spend the money on that, instead.

Is PR’s electrical grid a federal responsibility? I’d assume it was a local/territorial responsibility (now LUMA).

https://en.m.wikipedia.org/wiki/LUMA_Energy

This statement is a prime example of a fallacy known as false dichotomy. https://en.wikipedia.org/wiki/False_dilemma

I’m not convinced it is. The statement translates to:

“I think that the benefit for the community that infrastructure investment provides is so much greater than rebuilding the telescope, to the point that if I had absolute control of the limited gov budget I’d allocate all money to infrastructure.”

That’s debatable, but it doesn’t seem like a logical fallacy.

You can build infrastructure and a telescope.

That's a little over the top, if you want there to be a radio observatory in PR it would still be better to build a new one.

> (Also, the question of whether or not to make PR a state comes up periodically, and PR sides against it.)

All 3 referenda in PR since 2010 have favored statehood.

Notably many anti-statehood groups boycotted these plebiscites, and analysts noted that the questions were poorly structured. For example, the 2017 referendum had a result of 97% in favor of statehood... because only pro-statehood voters showed up.

https://en.wikipedia.org/wiki/Independence_movement_in_Puert...

They were boycotted because they were sham, non-binding referendums. There was never an effort from the mainland to introduce this into Congress seriously.

Therefore. Since nobody in Congress or White House lifts a finger, the referendum becomes just another political rally cry for the local pro-statehood party.

The United States and their political class have made it exceedingly clear that they favour the status quo -- both economically and politically -- at the expense of the island folk who suffer increasing austerity cuts and a deteriorating standard of living.

> was never an effort from the mainland to introduce this into Congress seriously

Statehood and its benefits isn’t something to be unilaterally demanded. Puerto Rico should have the option to declare independence. But it’s far too corrupt for political integration.

I wholly understand your point, but there's a huge power imbalance here. We can run all the referendums we want.

The US government has the full might of the US military, a reluctant political class and an economic interest in keeping the status quo.

There has to be cooperation in both sides for either statehood or independence, if decolonization is to be achieved peacefully. Sadly, there's no will to negotiate from the US gov’t.

About corruption, well, it’s true. Our ex-governor was recently indicted.

However, I also find corruption allegations a convenient way to perpetuate this image of Puerto Ricans as freeloaders—completely missing how much the mainland benefits from us economically, both as a tax haven and as a source of tax revenue (no IRS federal tax, but Jones Act import restrictions).

For more on economic benefits, think about this: a market of 2-3 million people locked in exclusively into US goods and markets due to colonial import restrictions.

Taxation without representation.

I thought Puerto Rico residents with income sourced from Puerto Rico didn’t have to file (or pay) US income tax. Is that mistaken?

That's correct! But federal income tax isn't the only way to get taxed.

1) All goods sold in PR have to pass by mainland US ports, raising living costs significantly. This means re-boarding into a US vessel on the mainland, then sailing to PR if coming internationally.

2) We pay other federal taxes (as freelancer, I pay social security tax among others).

3) Related to #1, customs taxes and levies on all goods transported, paid to the US Treasury.

This is an excellent overview: https://en.wikipedia.org/wiki/Taxation_in_Puerto_Rico

Too corrupt as opposed to say, Illinois? I forget the exact numbers now, but something like 6 of the last 12 governors have gone to jail for corruption, most recently Blagojevich. That's just at the top level; there's problems throughout the state... Not saying PR doesn't have problems, just pointing out actual states do, too.

Sorry, but I fail to see the relevance. Did Illinois declare independence from the US with its current apparently corrupt political class?

If corruption prevented political integration several current US states would not be integrated.

I find it exceedingly impossible that Puerto Rico is more corrupt than my home state of Louisiana.

Interesting, I guess my information was out of date.

Who deserve what, a gigantic concrete telescope from the 80s?

Maybe look past your sentimentality and notice that if money in Puerto Rico goes to anything it should be the electrical grid itself that manages to go down for weeks anytime something as mild as a tropical depression looks in the island's direction.

So, they should build something state-of-the-art there instead of what will effectively be a museum.

(This would probably be a lot easier to get funded if Puerto Rico were a state...)

More deserving then all 50 other states and D.C.?

But you could ask this question of any state(+DC). Therefore we should not do anything.

Untrue. We'd simply spend federal funds into the best bang for the buck not accounting for population scrappiness.

Pick one and I'd be happy to ask if it's more deserving than all the rest.

JWST.

I'm not familiar with this US state. I'll remind you that we were taking about Puerto Rico being more or less deserving than other states(&DC).

No. You were talking about that. I was specifically saying that we aim for the best bang for the buck on scientific projects with local scrappiness not of relevance.

Correction: MichaelZuo set the topic and I followed. You seem to be wanting to discuss a different topic which can be done elsewhere.

So, Maryland.

Puertoricans are American citizens by name only - they can’t vote, for example. It’s a colony, and US treats it as such - it doesn’t enjoy the privileges of actual US territory.

If you want to help, becoming a proper, independent country could be a good start. The majority of citizens opposes the current colonial status, as evidenced by several referendums, but, well, it’s not theirs to decide - because they are just a colony and aren’t allowed to vote.

Puertoricans wear the same uniform and fight in the same wars as all Americans so that folks can continue to say ignorant stuff like the comment above. My great grandfather did it. My grandfather. I did it. And I’m sure the tradition will continue.

From Title 8-ALIENS AND NATIONALITY CHAPTER 12-IMMIGRATION AND NATIONALITY SUBCHAPTER III-NATIONALITY AND NATURALIZATION Part I-Nationality at Birth and Collective Naturalization

All persons born in Puerto Rico on or after April 11, 1899, and prior to January 13, 1941, subject to the jurisdiction of the United States, residing on January 13, 1941, in Puerto Rico or other territory over which the United States exercises rights of sovereignty and not citizens of the United States under any other Act, are declared to be citizens of the United States as of January 13, 1941. All persons born in Puerto Rico on or after January 13, 1941, and subject to the jurisdiction of the United States, are citizens of the United States at birth.

It's not that the people of Puerto Ricans are lesser americans. It's that Puerto Rico itself as an institution has less rights. If a Puerto Rican moves to Alabama, they get the same rights and privileges, like voting, as anybody else.

Yes, they get to die for the USA. But they don't get a say like real citizens - no congressmen, no electoral votes, no senators. They do get to pay taxes though. Before you rant about how that's not important, I'd like to remind you of a certain group of English citizens who didn't have representation but were allowed to die and pay taxes for England.

Was I not a citizen until I was first able to vote for federal representation at the age of 25 after moving out of my hometown of DC?

Yes.

Real is probably the wrong term here, but certainly a citizen without the full suite of rights granted to you. If you have all the obligations without all the rights, you are a second class citizen. It's frankly absurd that someone can live within the US as a "citizen" without getting have meaningful representation.

Many Americans are second-class citizens because they live in areas where even if they DID vote, it wouldn't count for anything.

If Puerto Rico and DC were suddenly made part of California, nothing would change but suddenly they'd be "first class citizens"? (Besides now paying federal income tax)

That's just factually not true. Yes, the presidential election is fucked because the electoral college means that >70% of americans' votes are meaningless, but at the state and local level elections make a HUGE difference. And yes, that's not ideal, but it's a bit flippant and defeatist to write off all elections just because the presidential elections are screwed up.

I wish residents of DC didn't have to pay federal income tax :P

DC being part of California would marginally change the distribution of the House. Agreed the Senate & FPTP is undemocratic.

That's a weird argument. By the same logic current and former convicts are not citizens either.

In the strictest sense of the word they _are_, but they lose a significant portion of their rights as citizens, even after serving their mandated sentence and "paying their debt to society" or whatever. I would actually argue that ex-cons aren't citizens in the practical sense specifically because they lose out on a bunch of rights they could freely exercise before their conviction.

And before we get into a debate about whether ex-cons "deserve" rights, their sentence is supposed to be them paying their debt to society. Why shouldn't their rights be restored after that?

Well no - convicts are being punished for breaking the law.

People born, raised and still living in DC, Puerto Rico, US virgin islands, Guam, and Marianas are being punished for not breaking the law.

That's a different argument though. Punished or not, they are still citizens - so clearly whether you can or cannot vote doesn't change your citizenship.

See the first post of mine that you responded to:

> Real is probably the wrong term here, but certainly a citizen without the full suite of rights granted to you.

I acknowledged the thing you are objecting to before you started objecting. If you want to bikeshed a loosely used term after it's been acknowledged as being the incorrect term - have fun.

NOT a colony.... we're a territory. If you think puerto rico becoming it's own country and missing out on the aid, support and ease of travel provided by the federal government you are either malevolent or naive.

Puerto Rican residents can vote on everything aside from federal elections.

"Vote on everything aside federal elections" - what precisely did you think this means? We can't vote for the president, our elected officials to Congress can't vote on the laws that are passed. What "voting" can we do, other than yes, local elections?

> Puerto Rican residents can vote on everything aside from federal elections.

So, a colony? Taxation without representation. We might not get taxed IRS federal planillas, but all the levies and duties plus the harmful Jones Act beg to differ with your characterization.

The US is choking our economy in its current status. Statehood or independence, a binding referendum is urgent at this point.

Oh, and don't you remember how the US Supreme Court declared us second-class citizens recently? [0]

[0]: https://news.bloomberglaw.com/us-law-week/scotus-declares-u-...

Yukon is a territory. Here, the "territory" is just a pretty name for a colony. You can't vote, US constitution doesn't quite apply, you're getting peanuts from federal aid, and when there's a humanitarian catastrophe you're left for a month without electricity - but you are very welcomed in armed forces, because you're competent and when you die it doesn't matter to decision makers, because you can't vote. In short - you pay the price, but you don't get the benefits. How's that different from a colony?

And yeah, becoming a US state would be better than independence, but it won't happen, because - you guessed it, you can't vote. By becoming an independent country you could get major powers to compete to do business with you - I'm pretty sure China would invest billions into your infrastructure, you could literally become America's Taiwan.

> You can't [...] you're getting peanuts [...] you can't vote

It kinda feels like you're trying to shame Puerto Ricans for being the USA's bitches or something but I don't think that's reasonable. Puerto Ricans are US citizens and can move anywhere in the USA which is not only valuable and lets them send money home but shows that they're respected as just other Americans.

> By becoming an independent country you could get major powers to compete to do business with you - I'm pretty sure China would invest billions into your infrastructure, you could literally become America's Taiwan.

Leave the one country that helps you, though maybe not enough, to be the puppet of their enemy. Like that's not going to end in pain, but that's not your concern as an outsider trying to accelerate chaos.

I’m absolutely not trying to shame anyone; I’m pointing out they are being exploited.

> NOT a colony.... we're a territory

How did the US acquire said territory? And after they acquired it, what did they do to those who did not want their nation to be a "territory?" For those unaware, I'll give you a hint: it did not involve a hearty Socratic discussion followed by a game of badminton [0].

> If you think puerto rico becoming it's own country and missing out on the aid, support and ease of travel provided by the federal government you are either malevolent or naive.

This worked out rather well for the Hawaiians, who are currently having their groundwater poisoned by the US military [1], and their ancestral land acquired by mainlanders while they are made homeless [2].

In the recent non-binding referenda, and the bill to have a binding referendum which recently died in committee, there has been an option for "independence with free association" -- that is, an independent nation-state but with strong free trade and free travel agreements baked in [2]. Statehood is that, plus being subject to the whims of voters in Wisconsin, Idaho, et al. as to whether Puerto Ricans should be allowed funding for things. Keep in mind that there is no way out of this setup short of insurrection.

Given Puerto Rico has a distinct language, culture, etc. from the US, I can only assume we're deciding that the Westphalian model of the nation-state is not a consideration. Given this, I would also like to propose the following for statehood:

1. Korea

2. Vietnam

3. Iraq

4. Iran

5. Afghanistan

6. Somalia

7. Syria

8. Mexico

9. Haiti

10. Dominican Republic

These countries would surely flourish with the support and aid provided by the US federal government. And they were already, at one point or another, occupied by the US. So I can think of no reason not to annex them, short of naïveté or malevolence.

[0]: https://en.wikipedia.org/wiki/Utuado_uprising

[1]: https://www.theguardian.com/commentisfree/2022/jan/04/the-us...

[2]: https://thehomemoreproject.org/blog/the-hawaiian-homelessnes...

America acquired it fair and square, the same way nearly all land is acquired throughout human and animal history. Conquest. Those other areas haven't been annexed in the same way, because, after developments in the post WW2 era, acquisition evolved from outright colonization, to control using local proxies and a comprador class economically dependent on the core.

> Puertoricans are American citizens by name only - they can’t vote, for example.

The veterans who died for the continental US beg to differ.

> If you want to help, becoming a proper, independent country could be a good start.

The US government has the full might of the US military, a reluctant political class and an economic interest in keeping it that way. It's difficult -- whether you're pro-statehood or independence.

> The veterans who died for the continental US beg to differ.

Only if they skipped their history classes - dying for the empire is a standard part of being a colony.

The arrangement of Puerto Rico being a territory was a strategic decision. PR independence has a long history, but ultimately the economic and military benefits of being US citizens ended up outweighing the desire for independence. Being a self governing territory won out as being a sort of best of both worlds.

The US does not grant the states a right to become independent countries either.

and their residents pay taxes too.

Some taxes, not all. https://en.wikipedia.org/wiki/Taxation_in_Puerto_Rico

> Puerto Rico is an unincorporated territory of the United States and Puerto Ricans are U.S. citizens; however, Puerto Rico is not a U.S. state, but a U.S. insular area. Consequently, while all Puerto Rico residents pay federal taxes, many residents are not required to pay federal income taxes. Aside from income tax, U.S. federal taxes include customs taxes, federal commodity taxes, and federal payroll taxes (Social Security, Medicare, and Unemployment taxes).

Any attempt to give PR statehood or make it part of an existing state (Florida, I guess?) would meet with vociferous objection from Puerto Rico.

>As a child, I loved going there and its the earliest part of my childhood that I remember something motivating me to pursue science/math. Even in my later part of my life I was able to do some research with the observatory which kick started my current career.

Honestly seems like this is what they considered most when deciding to turn it into an education center.

> Another issue is that we have our brightest minds leaving the island because there's no fulfilling or well paying work to be done. The lack of this observatory is another reason more people will leave.

The problem with this line of logic isn't that it's wrong or even that it ignores the goal of scientific funding to produce scientific research. The primary problem with this line of argument is that it's equally good for Wyoming, West Virginia, and a dozen or more other deprived places that could all benefit substantially from the STEM-inspiration of a local megaproject.

West Virginia already has Green Bank, no?

They also published a video with some renders of the NGAT: https://www.youtube.com/watch?t=518&v=2qiu86-ZZdU

I really wish it had been built.

The thing is, even by rebuilding Arecibo the US (or more specifically, the NSF) would no longer own the largest radio telescope. China's 500m telescope [1] is already operational and while there are some minor differences when it comes to frequency range and field of view, there isn't much to justify the expenditure for another telescope in the US beyond mere political indulgences. From a strictly science based point of view, a new Arecibo is very hard to sell considering the implied costs.

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

The 500m telescope lacks transmitters - this is an important distinction.

> Fifth, Arecibo's larger secondary platform also housed several transmitters, making it one of only two instruments in the world capable of radar astronomy. ... The NASA-funded Planetary Radar System allowed Arecibo to study solid objects from Mercury to Saturn, and to perform very accurate orbit determination on near-earth objects, particularly potentially hazardous objects.

China's 500m telescope wouldn't be able to capture https://www.planetary.org/space-images/radar-images-of-aster... because it can't send a pulse.

https://ui.adsabs.harvard.edu/abs/2010DPS....42.1317B/abstra...

> We report Arecibo (2380 MHz, 13 cm) and Goldstone (8560 MHz, 3.5 cm) delay-Doppler radar observations of binary near-Earth asteroid (NEA) 65803 Didymos (1996 GT) obtained on five dates between November 14-26, 2003 during the asteroid's approach within 0.048 AU.

You'll note the Goldstone mention there and the "making it one of only two instruments in the world" from the wiki link on the 500 meter article

https://en.wikipedia.org/wiki/Radar_astronomy

> There is one remaining radar astronomy facility in regular use, the Goldstone Solar System Radar.

Thanks for a substantive and well-sourced comment.

There is a comment lower down saying Green Bank might add radar:

https://news.ycombinator.com/item?id=33233119

I’m not in a position to confirm whether that is true though.

https://greenbankobservatory.org/future-of-earths-defense-is...

> The National Science Foundation has awarded funds for the conceptual design of a higher-power radar system on the GBT – one that would be nearly 1,000 times more powerful than the proof of concept. In addition to a more powerful transmitter, NRAO and GBO, working with industry partners, will leverage new, solid-state amplifier and array receiving-system technologies to maximize the effectiveness of the new system. In parallel to this, as additional funding is allocated, the team plans to move to final design and construction activities, beginning in 2023.

> The GBT’s new radar capabilities will introduce a tool that astronomy has not had before, collecting data at higher resolutions and at wavelengths not previously available. NRAO and GBO also are developing advanced data reduction and analysis tools that have not been available before. The flexibility and increased performance of this new system will fill an important need for planetary defense, and also allow astronomers to observe asteroids, comets, planets and moons. The versatility of this system will contribute to many areas of science.

Does it seem like this would replace or improve upon what was lost at Arecibo?

From the page on the test - https://greenbankobservatory.org/successful-test-paves-way-f...

> Using the information collected with this latest test, the participants will finalize a plan to develop a 500-kilowatt, high-power radar system that can image objects in the Solar System with unprecedented detail and sensitivity. The increased performance also will allow astronomers to use radar signals as far away as the orbits of Uranus and Neptune, increasing our understanding of the Solar System.

> “The planned system will be a leap forward in radar science, allowing access to never before seen features of the Solar System from right here on Earth,” said Karen O’Neil, the Green Bank Observatory site director.

That use of the word "unprecedented" and looking at Uranus and Neptune suggests to me that it will go further than Arecibo did... three decades ago.

https://ui.adsabs.harvard.edu/abs/2000DDA....31.0803N/abstra...

> In October 1999 we obtained the first radar images of Saturn's rings, using the recently-upgraded Arecibo telescope operating at a wavelength of 12.6 cm. The opening angle of the rings was 19.9o, and dual-circular polarization data were collected over a period of 5 days. The resulting delay-Doppler maps have a range resolution of 100 msec and a frequency resolution of 2 kHz, corresponding to a spatial resolution cell of 15000 x 2000 km. Previous radar observations (e.g., Ostro et al. [1982] Icarus 49, 367) demonstrated the rings' high cross section and depolarization ratio, but did not yield 2-dimensional images.

The key thing with this is the radar astronomy rather than radio astronomy.

The tracking is likely what's at play for the Uranus and Neptune though. https://en.wikipedia.org/wiki/Arecibo_Telescope

> The round trip light time to objects beyond Saturn is longer than the 2.6-hour time that the telescope could track a celestial position, preventing radar observations of more distant objects.

Uranus is about 2.5 light hours Neptune is about 4 light hours from us. Double that for the round trip time.

The primary interesting part of this is getting the accurate ephemeris of near earth asteroids.

https://www.lpi.usra.edu/meetings/acm2008/pdf/8285.pdf

> Arecibo Doppler measurements (2380-MHz, 12.6- cm) of asteroid 99942 Apophis, obtained in August 2005 and May 2006, have been combined with optical astrometry reported through August 2006 to produce a new orbit solution.

https://www.sciencedirect.com/science/article/pii/S001910352...

> During these encounters the Arecibo and Goldstone radar stations collected seven Doppler and 22 delay measurements of Bennu. For a general description of radar astrometry see Yeomans et al., 1987, Ostro et al., 2002. This wealth of ground-based tracking data allows an extremely accurate description of Bennu’s motion (Chesley et al., 2014). The trajectory of Bennu is deterministic until 2135, when a close encounter with Earth leads to strong scattering and makes the knowledge of its future motion statistical.

---

So it looks like Green Bank will have improved transmitter and tracking. It won't have quite the sensitivity of Arecibo, but it's still one of the more impressive resources.

Thank you!

Some other "when digging around about radar astronomy and greenbank plans"...

https://www.wboy.com/news/west-virginia/green-bank-telescope...

> The Green Bank Observatory, in conjunction with the Goldstone radio telescope in California, has been monitoring the pair of asteroids over the two weeks following the experiment on Sept. 26. Observations found not only that the trajectory had been changed successfully, but that it exceeded the initial expectations for how large the shift would be.

From https://www.wvgazettemail.com/news/green-bank-telescope-help...

> Green Bank Telescope radar observations of the asteroid Dimorphos after it was deliberately struck by a NASA spacecraft on Sept 26 were used to confirm the success of the first-ever full-scale demonstration of asteroid deflection technology

The key here is that as mentioned Goldstone is the other radar astronomy capable observatory and its radar observations. RAdio Detection And Ranging. Those require the ability to transmit a radio pulse.

But absouyltely it's neat what they're doing with it.

How much does it cost?

I see it was built for $9.3M in 1960.

Now they're estimating the cleanup cost alone to be $50M.

Inflation adjusted - it should cost ~$95M to re-build. I'm not sure how if you'd need to include the total $50M cleanup on top of that.

Either way - if it can be re-built for $95M - that seems like a better deal than spending $50M to clean it up.

It is a big fiddly science instrument that requires constant maintenance, the benefit of cleanup is to get rid of that obligation. If we want to turn it into a museum or something, that might be worth considering. But that will require getting it into a safe state which is presumably lots of the cleanup cost.

$50M is a lot to spend for nothing. Can't the site just be fenced off (assuming it doesn't contaminate groundwater or endanger in-use facilities)?

If a private developer wants to take it over and turn it into a tourist destination, let them spend their own money. Throw them some tax incentives, maybe.

$95M would be a great deal to new science projects. India put an orbiter around Mars for less. We could start studying a distributed array approach to whatever comes after JWST.

The cost of cleanup (which includes restoring the forrest to its natural state) is really what kept it running for a long time-- basically within the budget horizon it was cheaper to keep it running at limp-along levels (which presumably contributed to the failure) than to shut it down.

I've long assumed that complete restoration being an assumed mandatory consequence of shutdown was itself a successful gambit from parties that wanted to keep the instrument operational. :)

Why does it need to be cleaned up?

I thought telescope mirrors had to be absurdly pure.

It seems like it would make for a super cool museum.

Arecibo was a radio telescope, like a satellite dish. The 'mirror' is a great big metal mesh hemisphere covering 18 acres of land in a mountain valley.

It's not an ideal museum location in and of itself because it's almost an hour drive out of the city across some not-sutiable-for-high-traffic mountain roads (see the beginning of the movie Contact for a pretty reasonable view of what the trip out and in is like).

Presumably the idea is that if we go around building stuff and just abandoning it we're doing unnecessary harm to nature as well as creating hazardous environments, e.g. when people go in to take the scrap metal and have stuff collapse on them.

> I thought telescope mirrors had to be absurdly pure.

It's a radio telescope, so think more along the lines of like a giant satellite dish. At the wavelength of the radio frequency signals, the tiny dust etc don't matter until they start to build up.

> Why does it need to be cleaned up?

The recent natural disaster(s?) in Puerto Rico damaged it massively, which given its sophistication and size likely means there's stuff strewn everywhere and facility damage. You don't generally want to leave government facilities to degrade to the extreme in disuse, so you still want to stabilize things to make it safe to traverse the area and be able to safely achieve the next goal of the facility and surrounding area.

There are 38,000 1mx2m perforated aluminum panels out there. I would pay a nice premium for them as a wall covering. Maybe not $50m/38000, but a good chunk of that. Having a section of the iconic telescope would be worth it. Now, are there thousands of people like me to make it work at scale?

Need to adjust for Puerto Rico's change in something like purchasing power parity since then, not just US inflation, depending on the mix of labor that was involved.

A single large collecting area still has sensitivity advantages vs arrays of smaller dishes. It was also used for radar and measuring distances to various objects in the solar system and the beam pattern from a single source there is vastly simpler than trying to use a phased array for the same task.

Arecibo had an active capability: radar mapping Venus most famously, that really can't be substituted with synthetic approaches. You can use aperture synthesis (from VLBA all the way to IVS) for greater resolving power, but they don't solve the coherent output problem.

It could transmit at 22 TW EIRP, a feature quite rare in smaller arrays.

While combined arrays can have equivalent reception resolution, I don't believe they are equivalent for transmission. I recall reading in a Carl Sagan book that one Arecibo could transmit and receive messages from another Arecibo anywhere in the galaxy.

It was supposed to be rebuilt as a phased array of about a thousand 10m dishes mounted on a steerable plate about 300m wide. That would have been some colossal engineering.

Have a look: https://www.youtube.com/watch?t=518&v=2qiu86-ZZdU

The unique capability is active radar. As far as I know, combined arrays of smaller dishes can't pulse out a radar beam, they can only sense via interferometry.

Unless there have been some advances in large scale wave forming, a giant dish is the only way to beam out powerful radar.

Could a large-scale array not transmit in the same way a phased array would on, for example, a Starlink antenna? https://en.wikipedia.org/wiki/Phased_array

The main purpose was militaristic and science benefited as a result. Like others have said, the technology has advanced to the point where it didn’t have much scientific value and we no longer need it to spy on the Russians so I highly doubt anyone is willing to pony up the billions just to have something cool and inspirational when it won’t even be cutting edge anymore

Arecibo was never intended to spy on the Russians, nor is it capable of doing so - it's facing completely the wrong way.

Arecibo did receive military funding, but that was because the military was interested in the behavior of the ionosphere. It was always a general science and technology development platform.

https://news.ycombinator.com/item?id=33234109

Soviet tech allowed members, and equipment, to cross the borders of the country. ;)

Again, this doesn't stand up to scrutiny. To pick up radar transmissions reflected off the moon, the moon has to be in line of sight for both the emitter and detector. Puerto Rico is just about the worst positioned place in the US for something to have the moon in line of sight at the same time as the soviet union, and the particular design of Arecibo further limits the angles it can be directed at, so it can't even look towards the horizon where it might conceivably stand a chance. It's fine for a telescope as the rotation of the Earth allows it to look at different parts of the sky at different times, but there's a reason no radio receivers for terrestrial communication are built that way.

Further, Arecibo works at frequencies of 10-40 MHz, substantially lower than even the lowest frequency radars. With secondary reflections you might be able to detect that a radar pulse had been detected, but determining where it came from or even what emitted it would be extremely challenging.

I suppose perhaps Cuba could have been spied upon with it, but again it's just the worst design for the application.

If you have any insight into the (dis)credibility of Steve Blank's talk, I would suggest opening a discussion on the talk page, so it can be removed.

> where it didn’t have much scientific value

EEEeeee.. don't confuse the weird biases in scientific research from publication incentives as being a true metric of scientific utility.

There is a tremendous bias in favor of "new" instruments because the low hanging discoveries made possible on something new (not even necessarily 'better' just different) haven't been made yet. But much of that research is extremely superficial and doesn't go on to contribute much to the forward body of knowledge -- it just helps churn out papers to support career progression.

Arecibo was thoroughly unmatched in several respects, particular as a radar[1]. It was also the premier instrument for validating observations made on synthetic aperture instruments since as a single aperture it's largely free of the artifacts that synthetic aperture instruments. Validation is scientifically critical but also doesn't tend to produce a lot of high profile papers.

[1] E.g. consider these images of the moon imaged using Arecibo as the transmitter and Green Bank Telescope as the receiver https://sservi.nasa.gov/wp-content/uploads/2014/05/craters2l...

Err, how was Arecibo able to spy on the Russians? Were there satellites going right over the dish?

On Wikipedia is the claim "The telescope also originally had military intelligence uses, including locating Soviet radar installations by detecting their signals bouncing off the Moon."[0], which gives this[1](by name, but unlinked) as its source. It would be interesting to know more.

[0] https://en.wikipedia.org/wiki/Arecibo_Telescope

[1] https://www.youtube.com/watch?v=ZTC_RxWN_xo

These sneaky scientists are always ready to fool silly military people into funding their extravagant scientific projects by promising it to have military uses.

This is probably a plot by some villain to make everyone think that the facility is abandoned. Once everyone withdraws from the area, it'll be used as a lair, from which the villain will direct the execution of his sinister plans.

That's a better plan than what the US government announced for it. An "educational centre for science, technology, engineering and maths (STEM)"? In the mountains of Puerto Rico, miles away from larger populated areas? I mean, while there was a telescope there, that actually made sense, but now that it's gone?

I believe that was the plot of Goldeneye.

Can we get another Bond film to fund rebuilding it?

Nowadays all you are gonna get is a fancy CGI reconstruction of the telescope...

Yeah, for it to work, we'd need to get Bezos to spend $700M+ on an Expanse reboot.

(After a few seasons, the set will pay for itself!)

The most sinister thing about this plot is using a radio telescope to control a satellite orbiting in LEO, wasting the poor engineers' time.

(Boris was lucky to be frozen in liquid nitrogen, consider it a mercy kill.)

No, you are wrong - GP wouldn't have said so if that would have been the case already..

If you want a government built lair, former icbm silos sometimes pop up on zillow

What I think this misses is that one of the main purposes of something like Arecibo is to be inspirational.

The coolness factor is something that helps science as a whole, from making kids interested in scientific activities and even boosting morale for scientists in the field.

Morale is one of those things that can't be quantified, but that can't be ignored.

Eh. I visited Arecibo almost 20 years ago, and even back then it was more historical monument pickled in time (I still recall some exhibits celebrating the Space Shuttle as the greatest thing since sliced bread) than anything scientifically inspirational, much less "cool". It very much felt neglected and the subsequent collapse, while sad, was entirely par for course.

I think that's at least equally the fault of the visitors center as anything about the instrument itself. The visitors center gave a very much working instrument a "historical monument pickled in time" feel.

I think there is a reasonable case to be made that the ultimate cause of the collapse was that not enough was spent on the visitors center, leaving guests with the impression that it wasn't a valuable instrument, leading to sustained absolutely minimal funding, leading to deferred maintenance (since they preferred to spend the money they got on actually operating!), leading to collapse.

So perhaps think of this in the future if you're about to criticize a scientific instrument for frivolous spending on visitor center upgrades.

The Shuttle is IMO still really cool and there are missions it could do like repairing Hubble or the initial stages of the ISS construction that would be really hard to do with the tiny little capsules we've reverted to. It's size and separate airlock alone give it abilities you can't get in any capsule flying today.

To be fair, we reverted to capsules because the Shuttle was so expensive that there was no additional will to spend the necessary amount (when accounting for defense contractor bloat) on an effective successor that wasn't a flying death trap.

Even those capsules (especially the one actually flying people right now) only barely got the funding they needed.

But at this point, why not build a new one instead? It's old tech at any rate.

Also, why not try an iterative approach? What would be the cost to build an extra copy?

In fact, doesn't the Hubble share parts with spy satellites?

The reason to not iterate on the Shuttle is that it was a fundamentally dangerous design, fixing the issues would be comparable to just making a new ground-up design. It would also be really expensive because the companies that made it have gotten used to the government teat. Modern American spacecraft are the 'new' Shuttle in that they incorporate all the safety lessons learned. The closest functionality-wise Shuttle successor would be crewed Starship.

Hubble shares a chassis with old spy satellites but IIRC all the optics have been replaced. There is a study ongoing for the potential of docking a Dragon capsule to it to boost its orbit and possibly service it via EVA.

I meant why not iterate on the Hubble. Yeah, it was expensive, but probably building a few more of them would be significantly cheaper than N times the cost of making one.

Iterating on Hubble would certainly be a bit more realistic, the Nancy Grace Roman Space Telescope - due to go up later this decade - can be considered somewhat of an iteration on Hubble in that it is also based on the same chassis with modernized optics, although IIRC it focuses on a different part of the spectrum.

Similarly, many proposed successors to JWST also iterate on the basic design and technology for JWST to include more mirror segments.

However, I suppose you're referring more to a silicon valley style iteration, which I think isn't worthwhile yet since ground based telescopes are already close to parity with Hubble and are cheaper to iterate on.

Ground based telescopes are still fundamentally limited by Earth's rotation and having to look through the atmosphere and increasingly having interference due to constellations like Starlink. Some spectra you just can't see with a ground based telescope because the light can't make it through our atmosphere.

There's a lot invested already in just getting the main mass up there and the core development of the system so building and installing small improvements can keep the investment useful for lower cost than replacing it.

Documentation on the spy satellite connection is sketchy but it seems to be designed similarly to an NRO satellite KH11 iirc but I think it was modified a lot and the more modern spy satellites might not be as readily convertible to deep space observation. So you have that work and the cost to loft it vs the cost to install some upgrades to and existing satellite.

Yeah. Maybe I’m just soft-hearted, but I really don’t think the benefit of this can be overstated. By dint of its location, configuration and instances of cultural cachet, this was a particularly unique and inspiring facility. I was pretty moved by it when I visited it in my 30s a decade ago - I can only imagine how many Puerto Rican elementary students were inspired to pursue science following a field trip to the telescope.

To me, rebuilding the scope is a no-brainer. Whatever it costs (assuming the number is in the low nine-digits), it’s worth it for the public relations value alone.

It’s too bad the Puerto Rican government is so cash-strapped - I wouldn’t be shocked if they could realize a positive ROI (based on tourism, research, local support, etc.) if the feds gave them the money that would go to clean-up and PR pursued reconstruction on its own. Unfortunately, while I think federal dollars could be put to efficient use here, I think the commonwealth has higher priorities they need to pursue.

The main purpose was militaristic and science benefited as a result. We no longer need it to spy on the Russians so I highly doubt anyone is willing to pony up the billions just to have something cool and inspirational when it won’t even be cutting edge anymore

Apparently Arecibo was the source for the cover art for Joy Division's Unknown Pleasures. Neat.

https://blogs.scientificamerican.com/sa-visual/pop-culture-p...

I've wanted to get the "Arecibo messsage" as a tattoo for a while now... https://en.wikipedia.org/wiki/Arecibo_message

Entirely unrelated, but I love that the actual album cover is a missing image on that article. They're talking about how iconic it is, and the image itself is the "broken image" icon - which is iconic in itself.

I don't see how $1-3M per year, for five years, is going to lead to "a world-class educational institution."

Makes zero sense, and NSF's best answer is that they are soliciting ideas about how. Arecibo is somewhat remote -- it's in a karst terrain that was chosen because it was so bumpy that it formed a convenient bowl for the dish. Its easy for the roads connecting it to San Juan to get shut down or degraded by storms. Without the telescope, it's really hard to imagine which students would aspire to go there. But it's a great place for.... A telescope.

Arecibo isn't remote. From San Juan I can get there in 40 minutes and it's directly off the 22 which is definitely not an easy freeway to be shut down short of a hurricane. It's also directly in between mayaguez and san juan both of which have a ton of students.

I guess I don't see how using 1-3 million dollars to operate an educational center is nonsensical. It's a central area between major universities, fairly flat terrain, northwestern coast so it's generally not going to see the worst of the storms and also has some existing infrastructure.

With that said it's a tragedy that they aren't going to rebuild the telescope in it's original glory.

World class means it attracts people from around the world.

It's 40 minutes from San Juan, which is on a relatively small island on the ocean.

And hurricanes have a habit of hitting there.

PR deserves great local institutions, but it is less accessible than most places that have much larger nearby population.

Puerto Rico is a fairly large (top 100 largest) island with international airports. It is larger than many other islands that have observatories.

Areceibo already WAS a world class telescope and was closer to an international airport than many other observatories.

The only valid point you've made is about hurricanes and earthquakes. However I haven't seen any discussion as to how those effect contruction costs at that site vs others.

I guess San Juan sprawls a bit -- took me almost 2h when I was there in 2020 (not too long after Maria), and we did face a partial washout and downed trees slowing down the last bit of the trip. But obv I trust a local that it's usually accessible :).

$1m a year is not gonna get much. It might not be the case, but it smells a bit like a token amount to keep something going - so they don't have to deal with the drama of closing the site.

In reasearch and education terms, that's literally peanuts. For comparison, the US Department of Energy operates 17 national laboratories, with an average budget of ~$700 million per year each.

I got to visit this place a couple of years before it collapsed. It was one of the coolest most cyberpunk things I've ever seen in real life.

Also featured as the centerpiece of a James Bond Movie (Goldeneye):

https://www.youtube.com/watch?v=vovVkvQhYEE&ab_channel=ostin...

And Contact.

As well as The X-Files [1], although apparently filmed in Vancouver – as with most of early X-Files…

[1]: https://en.wikipedia.org/wiki/Little_Green_Men_(The_X-Files)

Kind of a weird site for an educational facility. The Arecibo telescope was kind of in the middle of nowhere. That's a feature when picking a site for a radio-telescope, but not for education, especially when you don't have a cool-looking giant telescope to give people an excuse to make the trip

The US federal government should start a GoFundMe to pay the IOUs from all the times it raided discretionary spending on science, the arts and social security

On the plus side, the Green Bank Telescope has been fitted with a test radar transmitter and there are solid plans to put in a 500-kilowatt radar. This isn't quite a replacement for Arecibo, but it'll help fill the gap.

Very sad for the Puerto Rican people. My husband has great memories there.

Looking at the megatelescopes that they are building in Chile, i think its memory will soon be forgotten

https://en.wikipedia.org/wiki/Extremely_Large_Telescope

https://en.wikipedia.org/wiki/Giant_Magellan_Telescope

why? these are optical telescopes

https://xkcd.com/1294/

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?

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...

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.

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.

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.

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

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

Arecibo Memorial Skate Park.

Feels like a prime opportunity for a National Park. Restore it to the point where it won’t degrade further, add a museum, plantetarium, library, and preserve the land around the telescope. It’d be really neat! I’d take my kids to be sure.

I think (at least last time I looked into it, it may have changed since then) the problem was that some of the scientific equipment is heavy and suspended by cables which are degrading over time. I don't think it is like a battleship for example, which degrades into a battleship shaped hunk of steel which can be easily restored into a museum ship -- cables under tension fail catastrophically.

> cables under tension fail catastrophically.

I'm not sure there's much left, with the last failure: https://www.youtube.com/watch?v=0PZsblS1BUc

FWIW you can still buy Arecibo merchandise here

https://ao-galaxy-eshop.myshopify.com/

Surprisingly cool merch. Love the Arecibo Message tee, thanks for sharing

If you haven't read Ted Chiang's heartbreaking story about Arecibo (and parrots!), this seems like a good opportunity: https://electricliterature.com/the-great-silence-by-ted-chia...

Is it in a particularly climate susceptible place? Seems like if it was just hit by a hurricane, there will be more in the future. Perhaps not a good place in an eta of climate change?

It's up in the mountains in a bowl though so it's shielded in many ways from the worst effects of storms. It weathered them fine for about 50 years.

How about use all funds to build an interferometer to James Webb?

Plausible? Would be most advanced imaging ever made?

It's a testimony that its ROI is too bad for this human epoch and technology.

And yet we preserve places like Stonehenge, when modern calendars are considered superior.

Testimony that technology has advanced to more efficient and less location sensitive telescope designs?

Technology hasn’t progressed past the need for large, filled apertures.

It's decoupled of when that happens but tightly coupled with the rejection of that attempt.

I'm not sure what your point is here, but even if you look only at single-dish radio telescopes, humanity already has a better one in FAST.

Good. Build something better.

The cost to rebuild from scratch would be trivial for the combined endowments of America's top universities, who are surely the primary users

Harvard alone has tens of billions in its endowment.

...and yet, comments here are talking about crowdfunding??

This comment reveals a misunderstanding about how university research works. Individual professors are responsible for raising money from the government or private philanthropists to pay for research. University endowments are sometimes used for seed investments, but the vast majority of endowment investment into "research" is paying the professor salaries. Note that in most fields the grant-funded graduate students, postdocs, or research scientists are the ones who do the work. In this respect, one could compare university professors to startup-founders, with the return on the universities (meager) investment being indirect returns (the 50% administrative fee that is charged on grants) and fame to the university.

The general point of endowments is to support the university perpetually off the interest and not to spend it directly. For example, Stanford's $30 billion endowment returns $1.3billion per year but that only covers 21% of the universities operating costs.

Crowdfunding comes up whenever those with resources are indifferent to those with need.

People probably just don’t default think of universities. But yes universities have a history of funding stuff exactly like this. And it absolutely fits into their operant model.

Maybe the way for us normies to push for this is to donate to our alma maters and write letters/emails to alumni associations and administrations to propose joint funding of this across multiple schools.

> the way for us normies to push for this is to donate to our alma maters

Unless you put explicit conditions on your donation, chances are you're just going to fund the next round of salary increases for university administrators.

Even with explicit conditions, they often just shuffle other money around under the table.

"This $100 must be spent on science" => "route $100 of the general fund away from science"

Not really the point. Point is this could be funded by universities and that’s probably the only way for average any bodies to submit a (good/bad) idea to them directly.

The snark is overly done on the internet. To the point of dismissal.

"For England, James?"

"No, for me."

Time passed it.

FAST (five-hundred-meter aperture telescope) already exists and combining smaller ones is also an option.

FAST being in China is problematic.

Emblematic of decay of American power that we aren’t rebuilding it. And a betrayal of Puerto Rico, for which this is a symbol of pride.

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