MnAstro Forums

https://astronomynow.com/2020/08/11/are ... le-break/

One of the auxiliary cables that helps support a metal platform in place above the Arecibo Observatory in Puerto Rico, broke on Monday (Aug. 10) causing a 100-foot-long gash on the telescope’s reflector dish. Operations at the UCF-managed observatory are stopped until repairs can be made.

The break occurred about 2:45 a.m. (6:45 GMT) When the three-inch cable fell it also damaged about 6-8 panels in the Gregorian Dome and twisted the platform used to access the dome. It is not yet clear what caused the cable to break.

“We have a team of experts assessing the situation,” says Francisco Cordova, the director of the observatory. “Our focus is assuring the safety of our staff, protecting the facilities and equipment, and restoring the facility to full operations as soon as possible, so it can continue to assist scientists around the world.”

It JUST came back online last year after being damaged by hurricane Maria in 2017.

Damn. Maybe it’s showing its age.

CNN story with photo.

https://www.cnn.com/2020/08/12/us/areci ... index.html

I think it is not likely to be repaired.

Mark

The Wikipedia article has a lengthy section on funding concerns over the last 20 years. I wonder how much this affected inspections and maintenance? It will also no doubt affect decisions about repairs.
https://en.wikipedia.org/wiki/Arecibo_Observatory

Wow, that's more than just a gash. That's pretty heavy destruction on that part of the antenna dish.

I agree with Dave. That looks like heavy destruction. Unfortunately there aren't any photos circulating other than that one. All news articles reference that single photo.

Here’s the picture from the Astronomy Now article.

The main dish is 1000 feet in diameter. 100 feet is only 10% of that. It is a hard to tell for sure from this photo, but it looks like the missing section is a lot more than 10% of the diameter.

Here is another image

https://twitter.com/swiggumj/status/1293566041478619137/photo/1

Not that the damage is any less significant, but it's worth noting that the point of view can make a big difference in perception. In the comments you'll find a link to a picture of the Gregorian dome showing some of the damage it sustained.

It is hard to get a real sense of how big that instrument is. When I look at the stairways and catwalks on the azimuth truss, it adjusts my perspective.

Attended a lecture by Dr. Rivera-Valentin down at LPI in Houston. He is a planetary scientist using Arecibo to study solar system bodies. He shared these pictures from Arecibo. Not only does Arecibo recv, it transmits. They use it like a 1 Mega Watt radar to image solar system objects down to 2 meters resolution. Pretty incredible!!
.
. .
. .
. .
.

Found an aerial shot. Given the thing is SOOO big, the damage doesn't look that bad. I can't reconcile that shot from underneath (that damage looks HUGE!I) with this little punch kind of over there just off center. No, that's not a shadow.
. .
.
Now, there is some damage to the receiver, up top, but maybe not all is lost.

Friday night, 11/6, another cable broke at Arecibo. No one hurt, but more damage:

A main cable that supports the Arecibo Observatory broke Friday at 7:39 p.m. Puerto Rico time.

Unlike the auxiliary cable that failed at the same facility on Aug. 10, this main cable did not slip out of its socket. It broke and fell onto the reflector dish below, causing additional damage to the dish and other nearby cables. Both cables were connected to the same support tower. No one was hurt, and engineers are already working to determine the best way to stabilize the structure.

https://www.ucf.edu/news/a-second-cable ... erto-rico/

Yikes! It’s getting hard to see how they could fix it safely without lowering the whole suspended structure to the ground.

More information here:
https://apple.news/AtyET6IwMTI20Jeqq7KpdnQ
Unfortunately, if you don’t have apple news on your device and read it that way, the National Geographic site will open, which insists on getting an email address from you to read it, assuming you haven’t reached its 3 free article per month limit.

NSF has just announced they are decommissioning Arecibo!

Arecibo Observatory in Puerto Rico to be demolished:

https://www.nsf.gov/news/news_summ.jsp?cntn_id=301674

Not surprising, given the recent funding issues, but very disappointing nonetheless.

From: https://www.sciencemag.org/news/2020/11 ... dismantled

The Arecibo telescope’s long and productive life has come to an end. The National Science Foundation (NSF) announced today it will decommission the iconic radio telescope in Puerto Rico following two cable breaks in recent months that have brought the structure to near collapse. The 57-year-old observatory, a survivor of numerous hurricanes and earthquakes, is now in such a fragile state that attempting repairs would put staff and workers in danger. “This decision was not an easy one to make,” Sean Jones, NSF’s assistant director for mathematical and physical sciences, said at a news briefing today. “We understand how much Arecibo means to [the research] community and to Puerto Rico.”

Ralph Gaume, director of NSF’s astronomy division, said at the briefing the agency wants to preserve other instruments at the site, as well as the visitor and outreach center. But they are under threat if the telescope structure collapses. That would bring the 900-ton instrument platform, suspended 137 meters above the 305-meter-wide dish, crashing down. Flailing cables could damage other buildings on the site, as could the three support towers if they fell, too. “There is a serious risk of an unexpected and uncontrolled collapse,” Gaume said. “A controlled decommissioning gives us the opportunity to preserve valuable assets that the observatory has.”

Over the next few weeks, engineering firms will develop a plan for a controlled dismantling. It may involve releasing the platform from its cables explosively and letting it fall.

Sad . But predictable once the second cable failed.

Terrible news, but not surprising. In recent years funding for Arecibo operations has been in doubt. It was originally built with Defense Department funding as part of an anti-ballistic missile system. China has built a similar but bigger (500 meter) telescope but has had trouble recruiting scientists to work there.

The far side of the Moon would be an ideal location.

Yes, disappointing but understandable... here's another article:

Article at earthsky.org


Merle

Collected some additional shots of the August damage.

Apparently, the cable that snapped last week was only holding 60% of its designed load!!

As that's the case, complete collapse could come at any moment.
.
.

Well now it has completely failed:
https://www.sciencemag.org/news/2020/12 ... 7-year-run

rdavidjohnson63 wrote: ↑Tue Dec 01, 2020 11:40 am Well now it has completely failed:

.
Gravity SUCKS
.
.

2020, you're a son of a bitch.
. .
.
.
. .
.

I wonder if they saved any money this way. The demolition just got a little easier.