See the Dramatic Footage of the Collapse of Arecibo Observatory’s Massive 305-Meter Telescope

Starry Sky Above Arecibo Observatory

A starry sky above the Arecibo Observatory in Puerto Rico. Credit: University of Central Florida

The instrument platform of the 305-meter (1,000-foot) telescope at Arecibo Observatory in Puerto Rico fell at approximately 7:55 a.m. Atlantic Standard Time on December 1, resulting in damage to the dish and surrounding facilities.

No injuries were reported as a result of the collapse. The U.S. National Science Foundation ordered the area around the telescope to be cleared of unauthorized personnel since the failure of a cable on November 6. Local authorities will keep the area cordoned off as engineers work to assess the stability of the observatory’s other structures.

Top priorities are maintaining safety at the site, conducting a complete damage assessment as quickly as possible, and taking action to contain and mitigate any environmental damage caused by the structure or its materials. While the telescope was a key part of the facility, the observatory has other scientific and educational infrastructure that NSF will work with stakeholders to bring back online.

Arecibo Damage

Damage sustained at the Arecibo Observatory 305-meter telescope. Credit: University of Central Florida

“We are saddened by this situation but thankful that no one was hurt,” said NSF Director Sethuraman Panchanathan. “When engineers advised NSF that the structure was unstable and presented a danger to work teams and Arecibo staff, we took their warnings seriously and continued to emphasize the importance of safety for everyone involved. Our focus is now on assessing the damage, finding ways to restore operations at other parts of the observatory, and working to continue supporting the scientific community, and the people of Puerto Rico.”

The investigation into the platform’s fall is ongoing. Initial findings indicate that the top section of all three of the 305-meter telescope’s support towers broke off. As the 900-ton instrument platform fell, the telescope’s support cables also dropped.

Preliminary assessments indicate the observatory’s learning center sustained significant damage from falling cables.

Engineers arrived on-site today. Working with the University of Central Florida, which manages the observatory, NSF expects to have environmental assessment workers on-site as early as tomorrow. Workers at the observatory will take appropriate safety precautions as a full assessment of the site’s safety is underway.

“We knew this was a possibility, but it is still heartbreaking to see,” says Elizabeth Klonoff, UCF’s vice president for research. “Safety of personnel is our number one priority. We already have engineers on site to help assess the damage and determine the stability and safety of the remaining structure. We will continue to work with the NSF and other stakeholders to find ways to support the science mission at Arecibo.”

NSF intends to continue to authorize UCF to pay Arecibo staff and take actions to continue research work at the observatory, such as repairing the 12-meter telescope used for radio astronomy research and the roof of the LIDAR facility, a valuable geospace research tool. These repairs were funded through supplemental congressional appropriations aimed at addressing damage from Hurricane Maria.

Once safety on site is established, other work at the observatory will be carried out as conditions permit.


Although the platform’s fall was unplanned, NSF, UCF, and other stakeholders, including engineering firms contracted by UCF, had been monitoring developments at the 305-meter telescope that indicated an increased risk of a collapse.

In August, one of the 305-meter telescope’s cables unexpectedly detached. The remaining cables were expected to bear the load without issue as engineers worked on plans to address the damage. However, a second cable broke on November 6. Engineers subsequently found the second snapped at about 60% of what should have been its minimum breaking strength, indicating that other cables may be weaker than expected, and advised that the structure could not be safely repaired.

Both cables were attached to the same support tower. If the tower lost another cable, the engineer of record noted, an unexpected collapse would be the likely result. Since NSF’s November 19 announcement that it would plan for decommissioning of the 305-meter telescope,  surveillance drones found additional exterior wire breaks on two cables attached to the same tower. One showed between 11-14 broken exterior wires as of November 30 while another showed about eight. Each cable is made up of approximately 160 wires.

34 Comments on "See the Dramatic Footage of the Collapse of Arecibo Observatory’s Massive 305-Meter Telescope"

  1. What goes up, must come down. It’s odd that the videos were not released immediately after the collapse.

  2. CLIFFORD STANFIELD | December 4, 2020 at 5:43 am | Reply

    An icon for SETI. It had a small showing in the movie Contact and a fight scene in Golden Eye. Better equipment is available now but it’s loss raises nostalgia in me.

  3. Let the conspiracy theories commence…..It’s a cover-up! The dish was destroyed to protect US government secret meetings with aliens at area 51! You can clearly see the white puffs of smoke from the explosives used to bring down the towers!

    It’s a sad loss to the scientific community as a whole, RIP Arecibo. Hope to hear that they have plans (And hopefully funding…) to build something new at the site to continue the great work started there over half a decade ago.

  4. Look,we all know engineers of all stripes are Pinheads,,Pocket protector loving dweebs, nerds,geeks,weirdos….ummm, yeah. So,why in the hell are they soooo very very short sighted? 900 tons or tonns,tons, tonnes. A few million rolls or yarn is a waste! You should have brought in a Physicist or a better one as the case may be to have projected 500-1,000 yrs. out the tensile strength of every individual cable to guage it’s strength then compared to when it was first erected. Don’t be satisfied with the single strength, double strength…try 3x as strong, 4x as strong. The dopes who were responsible for erecting the dish as just a guilty as the dopes who, after the strand broke thought is was okay. You want to checkmate the pull of gravity? Do what those who’ve seen combat do,be secured 6 ways to Sunday. Multiple long guns,pistols, grenades,knives etc.

  5. The perils of deferring maintenance. No doubt something much better could be placed there.

  6. This is one of the best recordings I ever read. The videos were outstanding. Thank you for making things interesting. The basketball information of the lakers was excellent.

  7. It is so sad to see such an iconic landmark come down in a matter of seconds. As a native Puerto Rican, who has visited the site many times, I’m heartbroken. Puerto Rico has lost an Iconic Visitor Attraction. I hope it can be rebuilt as we need this site to once again be a part of the World’s Science exploratory site.
    Arecibo , You will be resurrected one day soon. Keep the faith. You were the strongest and you WILL live on..

  8. Just wondering….did they really fly a drone 24/7 to watch the equipment and the specific cable that failed?…kind of strange.

    • No it wasn’t 24/7. They were doing a routine inspection and coincidently caught the collapse.

    • Only conspiracy theory that I would support is the most obvious. This facility was too old, outdated ( in comparison to the Chinese ) too far away from USA and expensive to operate. We can romanticise and cry over it’s sad destiny ( similar we did with space shuttle ) but i can bet you that in less than a year we will have a proposal to build much larger dish and facility somewhere in continental USA!
      possibly privately owned and leased to USA research.

      You see, it’s all about money and power.

  9. Someone said make it 4x as strong. That’s easy to say but your TAX dollars pay for this and you and people like you get outraged when the government asks for more TAXES to pay for things like this. Everybody wants the moon and stars. But nobody wants to pay for it. And in any case, projects like this have to ask for funding from Congress and they DO ask for the money they need, but Congress often comes back with a fraction of the money requested, like 20-30%, or sometimes zero money. So projects like this end up operating on shoestrings and donations and gift shop profits. So sure, make it 4x stronger than needed. But who pays for that? This particular site will be cleaned up and that’s it. They won’t rebuild. And they won’t even have money for the clean-up.

  10. None of yerbuisness | December 5, 2020 at 10:35 am | Reply

    If you look at the coloumn at the back ….there seems to me either some sort of electrical charge or something detonated… the film in slow motion focusing on the black column at the back

    • *Facepalm* Please don’t encourage conspiracies. Rewatch all of it, and using critical thinking skills digest what you’ve seen. That tower you mention is the one the drone was watching. What you saw was the cables snapping, which when cables of their stature breaks, it is quite a sight.

  11. Now we don’t have to waist any more money, like were really looking for something. What we’ve believed to be, is already known and becoming more acknowledged by intelligence and military everyday.

    • First waste not waist. Second on my god, please do not speak when you have no idea what you are talking about. We have been exploring the stars, the vast universe!

  12. So a drone just happened to be there at the exact moment the cable failed?

    • I feel the same way. There is something behind all this.

      • OH. MY. GOD. Stop seeing something where there is nothing. They were doing a routine inspection via drone when it snapped. It was sheer luck, coincidences do happen. They have no reason to lie about this. Do you think the earth is flat too?

  13. For England, James!

  14. I still don’t get it, such amazing work just shatters within days. Uhmmmm, RIGHT! What is the true objective of all this? In a couple of years we will know when they state something like ” Now in Arecibo where the giant telescope stood for centuries is now going to be a so on & so on.” Only then would we know the meaning of this mark my words.

    • What are you talking about? You need to take your meds bud, and relax there is no conspiracy.

      Before you go spouting off some crackpot theories how about you actually look into what you’re talking about.

      What do you mean days?? You understand this has been around since !! 1963 !!. That is 57 years! It’s weathered multiple high level storms, the tropical environment, earthquakes, etc, the harsh conditions.

      Also not days, it sustained heavy damage in January from an earthquake, then in August a cable snapped, then November 6 a second cable snapped and then finally collapsed December 3. So if we simply go from Aug to Dec that’s approximately 120 ish days. Please cool your jets.

  15. Interesting there just so happen to be a drone watching at the moment of failure.

    • Interesting? Do you really think so?

      A structure has been exhibiting signs of likely collapse. Engineers have been inspecting it to determine if it can be fixed or if the damage can be mitigated. They’ve been using drones as it’s a large and difficult structure to inspect. One of them was flying when the final collapse happened. Accordingly, the footage from the drone was released with the footage from the CCTV cameras.

      Or we can have it your way. A secret organisation plotted for decades to bring down a radio telescope for… uh, secret reasons. After years of neglect and underfunding, they accelerated its demise through unspecified nefarious means. They used a network of drones to monitor their destruction of the telescope and managed to film the exact moment it fell. In order to keep secret their activities, they, uh… released the video onto the internet so that dumb people who think they’re smart could comment on websites to suggest there was a conspiracy. Ah ha ha ha ha! Oh, their evil plans.

      Which do you think is more likely?

  16. Guess he threw the paper towels a little hard.

  17. If I were a 305 meter telescope, I wouldn’t fall. Just sayin.

  18. Donald Raysor check out Don Ray.

  19. Just like highway construction, when a bridge is built, why not add a lane at that time to save the cost in the future at higher pricing. Why build an antenna to last 100 years when we’re used to building for 50 years? The only thing I can think of is future work. Fortunately, no one was allowed to film there because they knew it was failing. The question is when and what cost to save it at the time it’s usefulness has ended? With its condition, when did it stop being used. I suppose the people who decided this did not consider tourism.

  20. I think there’s a cover-up, tearing everything down and disposing of everything prior to a thorough investigation!!!. Somebody screwed up. Either one of the engineers adjusting the antennas over torqued the cables, some engineer miscalculated the lifting weight, manufacturing defect in the cable? Are these cables being used in other places i e supporting Bridges? Over the last several years they have added considerable weight in the antenna area. Did they consult the original engineering firm to see if it could handle the additional weight? I think whoever was in charge of the program the engineer’s and everyone should be fired. And Puerto Rico doesn’t have the infrastructure or equipment to properly maintain or inspect and item this complicated LOL. They probably spent more money repainting The Visitors Center then they ever did inspecting the cables. How about they publish the inspection logs for the cables over the last 50 years .

  21. Perhaps, it was sabotage. I think a thorough investigation is needed. Perhaps the salt sea are corroded the cables. Those who ignore history are doomed to repeat it

  22. Earthquakes salt spray from hurricanes almost 60 years of this torture will corrode steel wires to their breaking point. It’s like a bridge it needs maintenance it needs inspections if not things break and wires start to snap and approach critical failure point then there’s no point of repairs once it’s approached critical failure point. 900 tones is a lot of stress to put on 2 cables of 160 strands that have approx 20 to 60 stands broken on each one I’m no bridge builder but even i understand the laws of physics and gravity. What goes up must eventually come down, by man or nature.

  23. Insurance money?

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