I recently watched an interesting talk[1] about the NANOGrav project which looks for extremely low-frequency gravitational waves. The sources for these would be super-massive binary black holes, unlike the compact binaries ("regular" black holes and neutrons) that LIGO can observe.
They use radio telescopes to look for disturbances in the timing of millisecond pulsars due to gravitational waves, and they get about half of their data from Arecibo.
The project has been going for almost 15 years and they had just begun to see interesting stuff in their data. As the the project relies on continuous measurements of the pulsars, in order to detect variations in their timing, the presenter mentioned that more than six months of downtime would have a significant impact on the quality of their their overall data, and as mentioned on their page[2] many of the pulsars can only be measured by the Arecibo telescope due to its sensitivity.
Observatories come and observatories go [1]. It would be logical to have a transition plan to migrate science projects as old observatories are decommissioned and new ones turned up. Arecibo could go dark tomorrow due to disrepair (antenna assembly fails entirely, and 900 tons of suspended gear is going to do some serious damage upon failure) and the cost to repair and recommission is greater than available funds from UCF and NSF.
Edit: dredmorbius mentions in a comment below China has built a better observatory for this type of science [2]. Retask remaining science to other assets, decommission Arecibo.
I am confused as to why "repair the thing before it catastrophically fails" is not the best of the available options. Decommissioning a facility like this is a loss for science globally, even if there are alternatives available. Telescope time is precious.
You would have to dig into who is providing funding and how the funds are being spent by UCF, Universidad Ana G. Méndez, and Yang Enterprises Inc (the loose consortium tasked with O&M of the facility).
See the latest update on https://www.ucf.edu/news/update-on-arecibo-observatory-facil.... Just a month ago, cable sag surveys and safety assessments were done, and a structural monitoring instrumentation system was installed. I'd be curious what those reports show, and if this most recent failure was anticipated. If it wasn't expected, what was the value of the work last month?
I'm not saying that he should, everyone can spend their money as they wish, but just as a fun thought exercise, could a private, extremely wealthy entity do it? Say, could Jeff Bezos or Elon Musk just say "yep, I'll pay for all the repairs from my own pocket"?
Absolutely, but then they should assume control of operations to ensure a tight ship is run. If efficient use of funds is demonstrated, further funding (whether private, public, or crowdsourced) should follow. You don't want to encourage mismanagement of limited funds.
Edit: Upon further thought, I think it's an exceptional idea that SpaceX submit itself as an O&M vendor for NSF (and perhaps even NASA) RF/observatory facilities. Between launches and StarLink, they have demonstrated lean execution.
@ISL: Your point is noted, but SpaceX has a $50-100 billion valuation, access to capital markets, and StarLink is likely to be very profitable. I don't think it's fair to paint them to be in financial peril as they were during their earlier years. UCF's entire budget is $2 billion, and they can't scrap together a few millions dollars to properly care for Arecibo. UCF and SpaceX have each demonstrated their level of capability.
SpaceX has been so lean that they have been one launch away from bankruptcy. That isn't the right model for a scientific user-facility with a half-century expected lifetime.
Are you talking about back in 2008 when the third launch of the Falcon 1 failed to reach orbit? That was a long time ago. They are not near that situation now. The main goal of SpaceX is creating a human civilization on Mars. Seems to me like they do have the right combination of getting things done and the long view.
In theory you could do interferometry with a lot of orbiting radio telescopes. I'm no radio astronomy expert, but I can see a lot of practical problems with this idea.
For one thing, if you want the same signal-collecting power as the Arecibo observatory, you need dishes with the same total area. Since Arecibo is 1000 feet in diameter, if you put dishes on every one of the 12,000 satellites in the initial Starlink constellation, they would each have to be over 9 feet. That's about the same size as the chassis of the satellite itself.
In order to do anything useful with the collected data, the receivers need to have very precisely synchronized clocks, and their relative positions need to be known to within a small fraction of the wavelengths you're interested (which for Arecibo can be on the order of centimeters). I'm not sure whether GPS receivers alone would be enough to meet these requirements -- you might need to add atomic clocks to every satellite as well.
Now you have to think about how to aim the antennas. Presumably you can't just reorient the entire satellite, because its main job is to keep its ground-facing antennas aimed at the ground and its solar panels aimed at the sun. So you need to add a separate antenna pointing mechanism, with a fairly wide range of very accurate movement along multiple axes, so that all of the radio antennas can observe the same region of the sky simultaneously.
Presumably the Arecibo telescope itself is connected to fairly sensitive, low-noise, specialized signal processing equipment. You would have to take all of this equipment, design a space-rated version that can fit on a satellite, and then manufacture 12,000 of them. You also need to add enough solar panels to power it.
All of this would add a huge amount of mass to every satellite, which would make them way more expensive to launch. Note that this applies to to both the monetary cost and the opportunity cost of SpaceX's annual launch capacity.
Finally, the Starlink satellites have a roughly 5-year design lifetime, so it's not enough to build this colossally expensive telescope array once; you have to keep building and launching half a dozen replacements per day for as long as you want to continue using it. There's no way it would ever be cost-competitive with a ground-based observatory.
It's serious question, from the future.. (but no answer and downvoting - what's wrong ? I know Arecibo is very important)
..about radio telescope arrays, computer power and feasibility. Astronomers complain that they lost the sight of the stars because of Starlink. Could it be somehow compensated by an array of moving, smaller radio telescopes in orbit?
Britannica: 'The world’s most powerful radio telescope, in its combination of sensitivity, resolution, and versatility, is the Very Large Array (VLA) located on the plains of San Agustin near Socorro, in central New Mexico, U.S. The VLA consists of 27 parabolic antennas, each measuring 25 metres (82 feet) in diameter. The total collecting area is equivalent to a single 130-metre (430-foot) antenna.'
Arecibo is more important than the data it collects. If you are born on the island, it is perhaps the most conspicuous and inspiring scientific installation there. It’s a fascinating place to visit, beautiful and iconic. Its loss would be a loss for the children and aspiring scientists of Puerto Rico.
I was very interested in astronomy as a kid. I remember my mom taking me to visit the observatory as a kid. Somehow she got in contact with people there and I was able to tour other places.
While now I’m just a developer, it definitely sparked my curiosity and my like for science.
Sure, though in this case the whole point of the study is to observe the same pulsars over a very long period of time, so switching observatories can be tricky.
Does FAST cover most of the same pulsars Arecibo does?
Not a radio telescope like this, you want those in the middle of nowhere where there's as little stray radio signals as possible.
The city next to Green Bank telescope, the other major telescope for NANOGrav, has banned[1] cell phones and similar in order for the telescope to not be drowned in noise.
Do you need a building? Fully fund science, of course, but kill outdated platforms when resources can go to newer projects. I am very much in the support of science spend, but also very much for the efficient use of science dollars available.
I worked with some astrophysicists awhile back looking at these pulsar timing arrays[1] using Arecibo and Greenbank as data sources. Pretty fascinating stuff how you can identify strategic pulsars with desired frequencies and at positions where you can detect certain ranges of gravitational waves (typically super massive blackhole mergers).
Prior to LIGO's detections, they were hoping to be the first to detect and confirm the existence of gravitational waves but LIGO beat them to the punch. They were already concerned about defunding of efforts in radio astronomy and fighting to keep some of this hardware operational. These Arecibo hits are probably not a great addition.
Years ago my ex and I went to PR on vacation. Spent most of our time on Vieques, fantastic trip, but when we were still on the big island I dragged us all the way out to Arecibo. My wife was confused, there's nothing out there except some sort of observatory? It turned out to be our favorite part of the trip, they gave a good mini tour but seeing the thing in person was absolutely awe-inspiring.
Fun fact: Vieques was a US Navy bombing range for 60 years, which included several cases where Navy planes accidentally dropped bombs on civilian homes nearby.
I remember watching Contact and then reading the book and thinking I would like to visit the arecibo telescope on day. Didn't know they gave mini tours.
Our drive could have been for naught if someone was off that day or they were doing a study, no way to tell in advance. There's not much to give a tour of, just a large viewing room that was open to the public and so totally worth it, but someone did talk for about 20 minutes.
This shouldn't be downvoted, crowdfunding isn't a reliable stream of income and entirely unsuited to support decade-long experiments. Anything space-related is a multi-decade effort.
The other problem with crowdfunding is the complete lack of accountability on part of the founder. When the head of the European Space Acency Had A Word with his colleague at NASA about the delays with Galileo (about half of the experiments on Galileo were European) he could tell him that either the bird flies or all of Europe will forget about America and instead work with the Russians for the next 30 years. You can't do that on Gofundme, instead you lose out completely on that kind of project. No one sane is going to commit to a crowdfunded Arecibo when you don't know for certain that the crowd will support it 5 years hence.
I will not say that it should depend on crowdfunding, but in emergency situation, with the proper communication, that could be a way to get urgently some money for a specific situation like that.
Without waiting for states and large funding that usually take a lot more time to get
what, it should depend on private corporate funding instead? or maybe solely depend on the crumbs provided from government funding? if private citizens want to contribute money, i'm guessing most research teams starving for funding would not be opposed.
Research, especially fundamental research, should have stable multi year funding by the government. The current way, with many researchers being forced to spend more time on grant hunting than researching or teaching, and focus not dictated by scientific needs but by political aims (NASA!), and young researchers being ruthlessly exploited, is unsustainable.
Just compare the structures back when science, research and progress were taken seriously to now. It was the US government that gave humanity lasers, Internet, integrated circuits, battery tech, databases (Oracle!), satellite-based data gathering - almost all of what modern life grants us was founded back decades ago by massive government/military research programs.
Side note: this is also valid for Europe. We have all lost our collective focus to progress and advance to corporate greed and minimalist-government theories, while China has picked up the slack. The 21st century, I fear, will belong to China thanks to the collective actions of the last 30 years.
I don't think anyone receiving gov't funding would consider it stable. Every year, people have to justify their funding at the risk of having the funding removed. I have quasi-personal experience with the withdrawing of funding when Congress killed the Superconducting Super Collider. They killed it the same year that I was in high school and was going to spend time as an intern as several of my older classmates had done.
I know we're speaking the same base. Science funding is woefully short for pure scientific research endeavors. The US gave up on the race for discovery a long long time ago before I was born. The "why?" must always be backed up with a solid money making something. "Why?" can no longer be "because we don't know what we might find out" for a response that will get funded.
The scale is incredible. That's just the receiver platform suspended in the air that weighs 900 tons, not a tower. It's 100 meters "long", longer than a 747 and 3 times as heavy. It's like a steel road or rail bridge hanging in the air.
They use radio telescopes to look for disturbances in the timing of millisecond pulsars due to gravitational waves, and they get about half of their data from Arecibo.
The project has been going for almost 15 years and they had just begun to see interesting stuff in their data. As the the project relies on continuous measurements of the pulsars, in order to detect variations in their timing, the presenter mentioned that more than six months of downtime would have a significant impact on the quality of their their overall data, and as mentioned on their page[2] many of the pulsars can only be measured by the Arecibo telescope due to its sensitivity.
[1]: http://pirsa.org/20100068/
[2]: http://nanograv.org/announcement/2020/08/20/Arecibo.html